The Popular Science Monthly, June, 1900 / Vol. 57, May, 1900 to October, 1900

The emancipation of geology from the doctrine of catastrophism was a necessary step before progress could be made towards an understanding of the lands.The slow movements of elevation and depression of certain coasts in historic time were of great importance in this connection.Studies of geological structures at last overcame the belief in the sudden and violent upheaval of mountain chains, which, under the able and authoritative advocacy of Elie de Beaumont, held a place even into the second half of the century.But even when it came to be understood that mountains and plateaus have been slowly upheaved, it still remained to be proved that the valleys and canyons by which they are drained were produced by erosion, and not by fractures and unequal movements of elevation.Advance was here made on two lines.Along one, a better understanding was gained of the forms producible by deformation alone; along the other, sea currents, floods and earthquake waves, to which the earlier observers trusted as a means of modifying the forms of uplift, were gradually replaced by the slow action of weather and water.Processes of deformation were found to act in a large way, producing massive forms without detail—broad plains and plateaus, extensive domes, straight cliffs and rolling corrugations; and thus it was learned that the varied and detailed forms of lofty mountain ranges and dissected plateaus must be ascribed almost entirely to the processes of erosion.But it should be noted that in exceptional instances land forms initiated by deformation, so recently as to have suffered as yet only insignificant sculpture, may exhibit much irregularity. The most striking example of this kind, an example of the very highest value in the systematic study of land forms, is that afforded by the diversely tilted lava blocks of Southern Oregon, as described by Russell.F

Turning now to the second line of advance, it is noteworthy that so keen an observer as Lesley insisted, as late as 1856, that the peculiar topographical features of Pennsylvania, which he knew and described so well, could have been produced only by a great flood.But the principles of the uniformitarians were constantly gaining ground against these older ideas; and after the appearance in England of Scrope’s studies in Central France and of Greenwood’s polemic little work on ‘Rain and Rivers’ (1857), victory may be said to have been declared for the principles long before announced by Hutton and Playfair, which, since then, have obtained general acceptance and application.

Yet even the most ardent uniformitarians would, in the middle of the century, go no further than to admit that rain and rivers could roughen a region by carving valleys in it; no consideration was then given to the possibility that, with longer and longer time, the hills must be more and more consumed, the valleys must grow wider and wider open, until, however high and uneven the initial surface may have been, it must at last be reduced to a lowland of small relief.The surface of such a lowland would truncate the underground structures indifferently; but when such truncating surfaces were noticed (usually now at considerable altitudes above sea level, as if elevated after having been planed, and therefore more or less consumed by the erosion of a new system of valleys), they were called plains of marine denudation by Ramsay (1847), or plains of marine abrasion by Richthofen (1882).Today it is recognized that both subaërial erosion and marine abrasion are theoretically competent to produce lowlands of denudation; the real question here at issue concerns the criteria by which the work of either agency can be recognized in particular instances.In the middle of the century, not only every plain of denudation, but every line of escarpments was held by the marinists to be the work of sea waves; and it was not till after a sharp debate that the bluffs of the chalk downs which enclose the Weald of southeastern England were accepted as the product of ordinary atmospheric weathering, instead of as the work of the sea.Whitaker’s admirable essay on ‘Subaërial Denudation,’ which may be regarded as having given the victory in this discussion to the subaërialists, was considered so heterodox that it was not acceptable for publication in the Quarterly Journal of the Geological Society, of London, but had to find a place in the more modest Geological Magazine (1867), whose pages it now honors. So signal indeed was this victory that, in later years, the destructive work of the sea has been not infrequently underrated in the almost exclusive attention given to land sculpture by subaërial agencies. Truly, the sea does not erode valleys; it does not wear out narrow lowlands of irregular form between enclosing uplands, as was maintained by some of the most pronounced marinists in the middle of the century; but it certainly does attack continental borders in a most vigorous fashion, and many are the littoral forms that must be ascribed to its work, as may be learned from Richthofen’s admirable ‘Führer für Forschungsreisende’ (1886). As this problem can not be further considered here, the reader may be at once referred to the most general discussion of the subject that has yet appeared, in an essay on ‘Shoreline Topography’ recently published by F. P. Gulliver.G

At about the time when the subaërial origin of valleys and escarpments was being established in England, the explorations and surveys of our western territories were undertaken, and a flood of physiographic light came from them.One of the earliest and most important of the many lessons of the West was that Playfair’s law obtained even in the case of the Grand canyon of the Colorado, which was visited by the Ives expedition in 1858.Newberry, the geologist of the expedition, concluded that both the deep and fissure-like canyon and the broader valleys enclosed by cliff-like walls “belong to a vast system of erosion, and are wholly due to the action of water.”Although he bore the possibility of fractures constantly in mind and examined the structure of the canyons with all possible care, he “everywhere found evidence of the exclusive action of water in their formation.”This conclusion has, since then, been amply confirmed by Powell and Dutton, although these later observers might attribute a significant share of the recession of cliffs in arid regions to wind action.In a later decade, Heim demonstrated that the valleys of the Alps were not explicable as the result of mountain deformation, and that they found explanation only in river erosion.By such studies as these, of which many examples could be given, the competence of rivers to carve even the deepest valleys has been fully established; yet so difficult is it to dislodge old-fashioned belief that Sir A.Geikie felt it necessary to devote two chapters in his admirable ‘Scenery of Scotland’ (1887) to prove that the bens of the Highlands were not so many individual upheavals, but that the glens were so many separate valleys of erosion; and as able an observer as Prestwich, a warm advocate of the erosion of ordinary valleys by their rivers, maintained (1886), with the results of our western surveys before him, that fissures were probably responsible for the origin of the deep and narrow canyons of the Colorado plateau.

The tumultuous forms of lofty mountains ‘tossed up’ as they seem to be when viewed from some commanding height, are, in by far the greater number of examples yet studied, undoubtedly the result of the slow erosion of the valleys between them; but it should not be forgotten that regions of very recent disturbances—as the earth counts time—may possess strong inequalities directly due to deformation.The tilted lava blocks of Oregon have already been mentioned.The bold forms of the St.Elias Alps, also described by Russell, are regarded by him as chiefly produced by the tilting of huge crustal blocks on which erosion has as yet done relatively little work.An altogether exceptional case is described by Dutton, who says that on the margin of one of the “high plateaus of Utah a huge block seems to have cracked off and rolled over, the beds opening with a V and forming a valley of grand dimensions.”‘Rift valleys,’ or trough-like depressions produced by the down-faulting of long, narrow, crustal blocks with respect to the bordering masses, are occasionally found, as in eastern Africa, where the ‘Great Rift valley’ has been described by Gregory.Trough-like depressions of similar origin, but much more affected by the degradation of their borders and the aggradation of their floors, are known to European geographers in the valleys of the Saône and of the middle Rhine.But no rift valley, no depression between the tilted lava blocks, resembles the branching valleys that are produced by the erosive action of running water.

Thus far, while much attention had been given to the work of rivers, little or no attention had been given to the arrangement of their courses.It seems to have been tacitly assumed that the courses of all streams were consequent upon the slope of the initial land surface.The explicit recognition of this origin, indicated by the provision of a special name, ‘consequent streams,’ was an important step in advance due to our western geologists.The discovery soon followed that rivers have held their courses through mountain ridges that slowly rose across their path; the rivers, concentrating the drainage of a large headwater region upon a narrow line, cut down their channels as the land was raised.This idea first came into prominence through Powell’s report on the Colorado River of the West (1875), in which he gave the name, ‘antecedent,’ to rivers of this class.He believed that the Green river, in its passage through the Uinta mountains, was to be explained as an antecedent stream.Much doubt has, however, been thrown upon this interpretation.Other accounts of antecedent rivers have been published, and to-day the Green is not so safe a type of antecedence as the Rhine below Bingen, the Meuse in the Ardennes, or several of the Himalayan rivers in the gorges that they have cut through the youngest marginal ridges of the range.

Rapidly following the establishment of these two important classes of valleys came the recognition of the very antithesis of antecedent rivers in those streams which have grown by headward erosion along belts of weak structure, without relation to the initial trough lines.To these the term ‘subsequent’ has been applied.It is frequently in association with streams of this class that drainage areas are rearranged by the migration of divides, and that the upper waters of one river are captured by the headward growth of another.This is accomplished by a most beautiful process of inorganic natural selection, which leads to a survival of the fittest and thus brings about a most intimate adjustment of form to structure, whereby the more resistent rock masses come to constitute the divides, and the less resistent are chosen for the excavation of valleys.Many workers have contributed to the solution of problems of this class; notably Heim, in his studies of the northern Alps (1876), and Löwl, who showed that, in folded mountain structures of great age, the original courses of streams might be greatly altered through the development of new lines of drainage (1882).A valuable summary of this subject is given by Philippson in his ‘Studien über Wasserscheiden’ (1886).The extraordinary depredations committed by the waxing Severn on the waning Thames have recently been set forth by Buckman.The turning of side branches from the slender trunk of the Meuse has been recognized in France.Many remarkable instances of stream captures have been found in the Appalachians, where the opportunity for the adjustment of streams to structures has been exceptionally good.Hayes and Campbell have, on the other hand, emphasized the importance of drainage modifications independent of the growth of subsequent streams on weak structures, but governed by a slight tilting of the region, whereby some streams are accelerated and their opponents are retarded.It should be noted that the proof of the adjustment or rearrangement of drainage marks a victory for the uniformitarian school that is even more significant than that gained in the case of the antecedent rivers; for in one case a growing mountain range is subdued by the concentrated discharge of a large drainage area; but in the other case, the mountain slowly melts away under the attacks of the weather alone on the headwater slopes of the growing valleys.

The reason why all these studies of land carving are of importance to the geographer is that they greatly enlarge the number of type forms that he may use in descriptions, and that they recognize the natural correlations among various forms which must otherwise be set forth in successive itemized statements.The brief terminology learned in early school days, somewhat enlarged by a more mature variety of adjectives, is usually the stock of words with which the explorer tries to reproduce the features of the landscapes that he crosses, and as a result his descriptions are often unintelligible; the region has to be explored again before it can become known to those who do not see it. The longitudinal relief of certain well-dissected coastal plains, or the half-buried ranges of certain interior aggraded basins, may be taken as examples of forms which are easily brought home and familiarized by explanation, but which commonly remain remote and unknown under empirical description.

It may be urged that in many geological discussions from which geography has taken profit, consideration is given to form-producing processes rather than to the forms produced.This was natural enough while the subject was in the hands of geologists; but geographers should take heed that they do not preserve the geological habit.The past history of land forms and the action upon them of various processes by which existing forms have been developed, are pertinent to geography only in so far as they aid the observation and description of the forms of to-day.

Further illustration of the growing recognition of form as the chief object of the physiographic study of the lands is seen in the use of the term, ‘geomorphology’ by some American writers; but more important than the term is the principle which underlies it.This is the acceptance of theorizing as an essential part of investigation in geography, just as in other sciences.All explanation involves theorizing.When theory is taken piecemeal and applied only to elementary problems, such as the origin of deltas, it does not excite unfavorable comment among geographers.But when the explanation of more complicated features is attempted, and when a comprehensive scheme of classification and treatment, in which theorizing is fully and frankly recognized, is evolved for all land forms, then the conservatives recoil, as if so bold a proposition would set them adrift on the dangerous sea of unrestrained imagination.They forget that the harbor of explanation can only be reached by crossing the seas of theory.They are willing to cruise, like the early navigators, the empirical explorers, only close along shore; not venturing to trust themselves out of sight of the land of existing fact; but they have not learned to embark upon the open ocean of investigation, trusting to the compass of logical deduction and the rudder of critical judgment to lead them to the desired haven of understanding of facts of the past.

One of the bolder explorers of the high seas of theory is Powell, who defined in the term ‘baselevel’ an idea that had long been more or less consciously present in the minds of geologists, and which has been since then of the greatest service to physiographers.Powell and his followers, especially Gilbert, Dutton and McGee, have consistently carried the consequences of subaërial erosion to their legitimate end in a featureless lowland, and have recognized the controlling influence of the baselevel during all the sequence of changes from the initial to the ultimate form. It is not here essential whether such a featureless lowland exists or ever has existed, but it is absolutely essential to follow the lead of deduction until all the consequences of the theory of erosion are found; and then to accept as true those theoretical deductions which successfully confront the appropriate facts of observation. Only in this way can the error of regarding geography as a purely observational natural science be corrected. Following the acceptance of the doctrine of baselevels came the method of reconstituting the original form initiated by deformation, as a means of more fully understanding the existing form; for only by beginning at the initial form can the systematic sequence of the changes wrought by destructive processes be fully traced and the existing form appreciated. This had often been done before in individual cases, but it now became a habit, an essential step in geomorphological study. Naturally enough, the terms of organic growth, such as young, mature, old, revived, and so on, came to be applied to stages in the development of inorganic forms; and thus gradually the idea of the systematic physiographic development of land forms has taken shape. This idea is to-day the most serviceable and compact summation of all the work of the century on the physical geography of the lands. It recognizes the results of deformation in providing the broader initial forms on which details are to be carved. It gives special attention to the work of destructive processes on these forms, and especially to the orderly sequence of various stages of development, recognizing that certain features are associated with youth, and others with maturity and old age. It gives due consideration to the renewed movements of deformation that may occur at any stage in the cycle of change, whereby a new sequence of change is introduced. It gives appropriate place, not only to the forms produced by the ordinary erosive action of rain and rivers, but to the forms produced by ice and by wind action as well; and it co-ordinates the changes that are produced by the sea on the margin of the land with the changes that are produced by other agencies upon its surface. It considers not only the various forms assumed by the water of the land, such as torrents, rapids, falls and lakes, appropriately arranged in a river system as to time and place, but also the forms assumed by the waste of the land, which, like the water, is on its way to the sea. In a word, it lengthens our own life, so that we may, in imagination, picture the life of a geographical area as clearly as we now witness the life of a quick-growing plant, and thus as readily conceive and as little confuse the orderly development of the many parts of a land form, its divides, cliffs, slopes and water courses, as we now distinguish the cotyledons, stem, buds, leaves, flowers and fruit of a rapidly-maturing annual that produces all these forms in appropriate order and position in the brief course of a single summer.

The time is ripe for the introduction of these ideas.The spirit of evolution has been breathed by the students of the generation now mature all through their growing years and its application to all lines of study is demanded.It is true that the acceptance of inorganic as well as of organic evolution is often implied rather than outspoken; yet evolution is favorably regarded, as is proved by the eagerness with which even school boards and school teachers, conservatives among conservatives, hail the appearance of books in which the new spirit of geography is revealed.In the last years of the century, the school books most widely used in this country have made great advance in the explanatory treatment of land forms. Tarr’s Physical Geographies and Russell’s monographic volumes on the ‘Lakes,’ ‘Glaciers,’ ‘Volcanoes’ and ‘Rivers’ of North America, all presenting land forms in an explanatory rather than an empirical manner, have been warmly welcomed in this country.Penck’s ‘Morphologie der Erdoberfläche’ (1894), although largely concerned with the historical development of the subject, presents all forms as the result of process.De Lapparent’s ‘Leçons de géographie physique’ (1886) treats land forms generically; and a second edition of the book is called for soon after the first.‘Earth Sculpture,’ by James Geikie (1899), and Marr’s ‘Scientific Study of Scenery’ (1900), carry modern ideas to British readers.There can be little doubt that the books of the coming century will extend the habit of explanation even further than it has yet reached.

This review of the advance of the century in the study of land forms, the habitations of all the higher forms of life, might have been concerned wholly with the concrete results of exploration, as was implied in an earlier paragraph.Travels in the Far East of the Old World, or in the Far West of the New, have yielded fact enough to fill volumes.But such a view of the century has been here replaced by another; not because the first is unimportant, for it is absolutely essential, but because the second includes the first and goes beyond it.Not the facts alone, but the principles that the facts exemplify, demand our attention.These principles, founded upon a multitude of observations, are the greater contribution of the closing to the opening century in the study of the Forms of the Land.

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THE NEW YORK BOTANICAL GARDEN.
By DANIEL TREMBLY MACDOUGAL,
DIRECTOR OF THE LABORATORIES.

A botanical garden is a museum of plants in the broadest sense of the term, and its chief purpose is to represent, by means of living specimens so far as possible, the principal types of the vegetation of the globe. It is obviously impossible to cultivate on any small area more than a few thousand of the quarter of a million of species in existence, and hence the plantations are supplemented by preserved specimens to illustrate the forms, which, by reasons of limitation of space, climate and soil, cannot be grown in the locality. In addition the species which formed the vegetation of the previous geological periods are represented by fossil specimens completing the history of the plant world so far as it is known, and yielding suggestions as to the descent of the present types.

Two general educational purposes are served by an institution of this character.Its collections are arranged to present information on the form, relationship, mode of life, habit and general biological character of the principal types of vegetation, in such manner as to be capable of comprehension by persons unacquainted with the technical aspects of the subject.Further interpretation of such facts may be made by means of books, journals, and lectures devoted entirely to this phase of the subject.

The material accumulated for the exploitation of popular knowledge of plants also affords an excellent basis for the induction of students into the more strictly scientific aspects of botany, and when supplemented by laboratories furnished with apparatus, microscopes, and other instruments of precision, the activities of these students may be carried beyond the frontiers of the subject in the investigation and discovery of new facts and phenomena.This extension of the boundaries of knowledge concerning the plant world may be carried on to advantage, only when a library is at hand, which contains all of the more important literature bearing upon the subject.The descriptions of the results of such researches should be made in publications devoted exclusively to this purpose, in accordance with the practice of all the more important botanical institutions in the world.

The general scope of the New York Botanical Garden has already been described by the writer in a previous number of this magazine (January, 1897).The greater part of its actual construction and organization has taken place in the last three years, and it has now entered upon the discharge of its chief functions.

The Garden comprises two hundred and fifty acres of land in Bronx Park, in the City of New York, which was set aside for that purpose by the Department of Public Parks in 1895.A fireproof museum building of stone, brick and terra cotta, 308 by 110 feet, has been erected for the Garden by the city in the western part of the grounds, near the Bedford Park Station of the New York Central Railroad.The building has a basement floor and three stories, with a total floor space of nearly two acres, and a window area equal to half that of the floor area.The basement contains a lecture theater capable of seating seven hundred people, two large exhibition halls, preparation rooms, constant temperature laboratory, offices and storerooms. The first floor is devoted to a collection of economic plants, and the temporary installation of useful products in the way of foods, drugs, timbers, woods, fibers, gums, waxes, resins, oils, sugars, starches, poisons, utensils, etc., gives hints as to the great diversity of uses that may be made of vegetable products, together with an illustration of their method of preparation and their derivation.

The second floor is given over to an exhibit of types of all of the more important families and tribes of plants, from the simplest and most minute, to the highest and most complex. Specimens, models, fruits, seeds, drawings and photographs are used to bring the principal facts clearly before the observer. A set of swinging frames running parallel to the cases containing the types of the flora of the world, are used to display specimens of the plants found within a hundred miles of New York City. A number of special microscopes have been constructed for the purpose of forming a perfect exhibit, which will enable the visitor to see some of the more salient features in the minute structure of some of the plants in the cases.

The third floor contains the library, herbarium and laboratories.The library occupies a stack room extending to the rear of the middle of the building, two small storerooms and a large circular reading-room, under the illuminated dome.Here are assembled the botanical books of Columbia University, as well as those accumulated by the Garden, now numbering more than eight thousand volumes, with no reckoning of unbound separates and pamphlets.The collection of botanical periodicals is nearly complete, and the library is especially rich in literature concerning the mosses, ferns, and the flora of North and South America.

The main herbarium occupies a room in the east wing, eighty-five by forty-seven feet, and connected with it are storerooms and offices adequate to its administration.Windows on all sides of the main room and skylights give ample illumination.The number of mounted specimens on the shelves is not less than three quarters of a million, including the herbarium of Columbia University, which is deposited here in accordance with the agreement between the two institutions.The collection is especially rich in fungi, embracing the collections of Ellis and other eminent mycologists.A large amount of material of great historic value in connection with the work of Dr. John Torrey and the earlier botanical development of America is included. Accessions are being made to the herbarium at the rate of fifty to a hundred thousand specimens annually.

The laboratories consist of a series of rooms facing northward and westward, with special facilities for taxonomic, embryological and morphological investigations.Physiological and photographic darkrooms, the experiment room for living plants and chemical laboratories offer especially ample opportunities for the record and development of practically all phases of plant physiology.The laboratories, library and herbarium are open to the graduate students from Columbia University, in addition to those from other institutions of learning who may register directly at the Garden.The latter, in return, have the privileges of students at Columbia University.

A weekly convention of all of the workers in botany in New York City is held in the museum, at which the results of recent researches are given or an address is made by an invited speaker from out of the city.

The area of the Garden presents a very irregular topography, comprising, as it does, a half mile of the valley of the Bronx River, low marshes and swamps, artificial lakes, open glades, with heavy peaty soil, upland plains with gravelly sandy soil, granite ridges, and about seventy acres of natural forest.About forty acres of this forest consist of a dense grove of hemlocks, which has never been seriously disturbed by the hand of man. It is truly remarkable that the City of New York should include within its boundaries a primitive forest of this size, and this invaluable feature is to be preserved forever by a special contract between the Garden and the Department of Public Parks. Since a hemlock forest is a climactic formation, and is not replaced by any other growth unless cut down, it may be expected to endure through the present geological epoch, barring the accidents of flood, storm and fire. The great diversity of conditions offered by the natural features of the Garden gives it a very rich population of indigenous plants. A census of the ferns and seed-plants at the time the tract was converted to its present purpose showed nearly a thousand species.

The entire area has been handled most sympathetically by those in charge of the architectural features of the Garden.The buildings were erected in the more open western part of the grounds, which offered the least valuable landscape features, and the surface around them has been improved by plantings.The natural beauties of the tract have been most zealously guarded from disturbances of all kinds.The attractive panoramas of wild woodland and stream offered to the artist and lover of nature have been left absolutely untouched, but made more valuable by increased ease and safety of access.

A number of special biological groups of plants have been established in suitable places in various parts of the Garden.The trees are in the arboretum east of the Bronx on the side and summit of a long ridge; unassorted and reserve material of all kinds is kept in the nurseries on the eastern slope of the same ridge; the salicetum is established on the border of the marsh in the northern end of the Garden, giving the willows and poplars the conditions under which they grow best. The fruticetum occupies an adjoining upland plain underlaid with gravel to a depth of twenty feet, affording space for the cultivation of a large number of shrubs, while the conifers are located on slopes to the westward of the hemlock forest. The viticetum is along the western edge of the forest, and the trellises of logs and timbers, extending for a length of six hundred feet, give suitable support to the vines. The herbaceous plantation occupies an open glade to the westward of the forest, and lies between two granite ridges. It is traversed through the middle by a small stream widened at places into lagoons for aquatic forms. About twenty-two hundred species are now in cultivation in this plantation. The wide border plantations which are established along the boundaries also offer opportunities for the growth of a great variety of trees, herbs and shrubs.

The horticultural houses, also erected by the City for the Garden, are located in the western part of the grounds at some distance to the south of, and facing, the museum.A palm-house, with a total height of dome of ninety feet, is the central feature, from which lower ranges extend on either side, making a total length of front of five hundred and twelve feet.The horticultural houses, as well as the museum, are heated by steam furnished by a power house beside the railroad on the extreme edge of the Garden.

The collections of living plants in the plantations are arranged in the same system as the synoptic collection in the museum.Every plantation contains species of similar habit, and the horticultural houses are used for the cultivation of forms which may not endure the outdoor climate of this locality.Not only are the plants from warmer zones grown under glass, but when it is desired to develop native species out of their season, they may be forced and brought to full development and bloom in the winter.

The construction of driveways and paths is being prosecuted by the Park Department with all available funds at their commands.

Public appreciation of the natural beauties of the Garden, and of the phases of botany illustrated by its collections has been most gratifying, as shown by the great and constantly increasing number of visitors.The series of popular lectures given in the museum on Saturday afternoons have been well attended.The Journal of the Garden, which serves as a means of communication with its members, brings to the notice of its readers interesting facts in botany, horticulture and forestry, and records a constantly swelling list of gifts of books, specimens and plants.

The library, herbarium and laboratories have been open for only a few months, yet twenty-two students have taken advantage of the facilities thus afforded during the collegiate year now closing. Investigations of importance have been carried forward by these students, by members of the staff, and by the members of the staff of Columbia University. The results of some of these investigations have been published in the Bulletin of the Garden, which also contains the official reports of the organization. Papers written by members of the staff or students are reprinted from the periodicals in which they appear as contributions, while a fourth series of Memoirs has been found necessary for the presentation of papers of great length.

Not the least important of the investigating functions of a garden consists in its participation in the exploration of remote or unknown parts of the world in an effort to obtain a better knowledge of the plant population of the earth.During the brief period of its activity the Garden has already carried out work of this character in the Rocky Mountains and in Porto Rico.

The ordinary work of the Garden is maintained by the income from its endowment fund, by the annual dues of its members (now numbering over eight hundred) and by an annual appropriation by the City.Its board of managers is authorized to hold and administer trust funds, and it is hoped by the aid of gifts or bequests for special or general purposes to expand its usefulness in directing investigation.Already it has been favored by a bequest of a considerable sum of money by the late ex-Chief Justice Charles P.Daly, which may be devoted to any purpose determined by the board of managers.

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GAS AND GAS METERS.
By HUBERT S. WYNKOOP, M. E.

What is the matter with our illuminating gas? Why is its quality so poor? Why is it that our bills are creeping up, in spite of the fact that the rate per thousand cubic feet is going down? These are questions that periodically recur to the mind of every householder.

Just why the public has not been educated into a correct understanding of the gas situation is hard to say, unless it be that an inbred prejudice against believing the word of any corporation has led to an utter repudiation of such explanatory statements as may emanate from time to time from the gas office.And it must be admitted that many of the explanations are misleading, either through the intention of the superior officials or by reason of the ignorance of their subordinates.

Hardly has the chill of shortening days driven us indoors in the early twilight before complaints of poor gas become epidemic. Now, what is ‘poor’ gas? Is the gas deficient in light-giving constituents, or is it merely burned in such a manner as not to afford a satisfactory illumination?

The charter of Greater New York requires that the illuminating gas supplied throughout the city shall be of at least twenty candle power, or illuminating quality, or richness—that is to say, if we burn this gas in a standard burner at the standard pressure (or at as near this pressure as may be), so that the rate of consumption is five cubic feet an hour, the flame thus produced shall be equivalent to twenty standard sperm candles, each burning at the rate of one hundred and twenty grains of sperm per hour, and all bunched—if such a thing were possible. There can be hardly any doubt but that all the gas sent out from modern gas works fulfills the above requirement. Indeed, my own tests give results ranging from twenty-two to twenty-eight candles, with an average of about twenty-four. Manifestly, the gas sent out is not ‘poor.’

Nevertheless, the fact that the gas as manufactured is of the required candle power is no indication that the product as delivered to the consumer will give a similarly satisfactory test.Distribution of gas is attended with many perplexities, not the least of which is condensation.The illuminating hydrocarbons, or light-giving constituents held in suspension in the gas, are not so firmly fixed therein as to be unaffected by the size of the pipe, the character of the internal pipe surface, and barometric and thermometric variations. The transmission of gas causes, therefore, a loss of candle power ranging from a small fraction to several candles, although it is possible to conceive of conditions so extraordinarily favorable that the illuminating quality of the gas might be actually improved by distribution.

It will be readily understood from this explanation that tests made at the gas works, or even at points arbitrarily selected at a certain distance from these works, are hardly calculated to satisfy the consumer. For this reason I have preferred, in conducting these tests, to sacrifice to some degree the accuracy that obtains in laboratory experiments, in order to test gas samples taken from the main directly in front of the complainant’s own premises. I argue that the consumer cares little or nothing as to whether the gas as manufactured complies with the law, or whether tests made at a point perhaps a mile away from the works show the required candle power; but that he does want to know what is the quality of the gas passing in at his service pipe. The method of collecting and transporting to a laboratory the gas samples enables one to say with positiveness that the gas at the point of complaint has an illuminating power of at least so many candles, and that it may be even one candle better than the tests indicate. The figures thus obtained range from twenty and a half to twenty-five. So, then, the gas delivered to the consumer is not ‘poor.’

Hygienic reasons demand that the impurities in the gas shall not exceed a definite percentage.Whatever effect these impurities may have upon the candle power has been covered by the tests above explained, so that any further consideration of these impurities may be omitted here.

It is always a difficult matter to convince an indignant householder that the quality of the gas supplied to him is satisfactory. He knows perfectly well that he is not getting the desired result, and no explanation, however elaborate, as to candle power will placate him, unless it be supplemented by a further statement detailing the cause of the trouble. When you are trying to draw water in the bathroom while the cook is filling the washtubs in the basement, do you say the water is ‘poor’? Why, then, should you characterize the gas as ‘poor,’ when people nearer to the gas works than you are happen to be drawing heavily upon the common gas main? Imagine, if you please, a long gas main, with consumers tapping in at points throughout its entire length, and with a gas holder forcing the gas in at one end. Since there is a loss of pressure, caused by the transmission, it follows that the pressure will be higher at the gas holder than anywhere else along the line, the difference in pressure depending, roughly, upon the size and length of the pipe and upon the amount of gas flowing. Now, for any one customer the size and length of pipe will remain constant, but the flow of gas along the line will vary from hour to hour, consequently the pressure at his house may be expected to vary from hour to hour.

The unit of measurement of gas pressure is that pressure which will cause a difference of water level of one tenth of an inch in the two legs of a V-shaped tube when one end is connected with the gas main and the other end is left open to the outer air.Ten tenths, or one inch, is the standard, or normal pressure.

Any appliance—even a gas-burner—operates to best advantage under certain well-defined conditions.Depart from these conditions, and the efficiency of the device is impaired to an extent depending largely upon the nature of the appliance under consideration.For example, burn an incandescent lamp at fifty per cent.above normal voltage and it breaks down; burn a gas jet at two hundred per cent.above normal pressure, and it still operates—how satisfactorily ‘deponent sayeth not.’Now, the gas-burner is supposed to operate to best advantage at ten tenths of an inch.At this pressure the flame is neither so wavering as to be affected by every chance draught, nor so rigid as to permit the gas to blow through without being properly consumed. Below the normal the flame decreases; above, the light is increased somewhat, but not by any means in proportion to the increase in the gas flow. Thus we see that the satisfactory employment of gas as an illuminant depends upon the maintenance of a pressure high enough to deliver the required amount of gas, but not so high as to cause wasteful consumption.

Turning back now to the gas main, let us consider the pressures actually existing. Exhibit 1 is a photograph of a twenty-four-hour record of pressure at a point not far from the works. The radial lines represent time, and there is a line for each quarter of an hour. The circles represent pressure, there being one circle for each tenth of an inch. Starting at E, the point at which the record begins, and following the irregular line clockwise, one may readily determine the fluctuations of pressure and the time of their occurrence. Interpreting the diagram, we find that the pressure was slightly above the normal until 4.30 P.M. (A), when the works began to raise the pressure little by little, in order to compensate for the increased loss due to increased flow through the mains. At 6.15 P.M. (B), the works ceased increasing the pressure. While this increase lasted—from 6.15 P.M. (B) to 10.15 P.M. (C)—our friend near the works suffered under twenty-one tenths pressure, the gas blowing merrily through the tips and the meter conscientiously registering gas wasted as well as gas utilized. From 10.15 P.M. (C) the pressure falls by steps during the ensuing two hours, finally reaching eleven tenths just after midnight (D), which latter pressure is quite steadily maintained until the following forenoon.The service from bedtime to dinner time should have proved quite satisfactory.One would naturally expect to find this consumer complaining of high bills, however.

Visiting the fellow at the distant end of the line, we find conditions widely at variance from those already considered. Exhibit 2 tells a new story. The recording gauge was placed in service at 4 P.M. (E), and shortly afterward (A), the pressure began to fall.The jets grew dimmer and dimmer, while the Welsbach mantles became petticoats of red, with hems of white at the bottom. No wonder this man complains of ‘poor’ gas, while some learned friend, dropping in for an evening cigar, explains that there is ‘air in the pipes.’ The one consolatory reflection is that, at all events, the poor fellow had a good light to undress by (B to C).

Exhibits 3 and 4 come from my own residence. Together they form a ‘before-taking’ and ‘after-taking’ advertisement—not of medicine, but of a gas governor. The fact that I am located at a considerable distance—several miles—from the works, and am supplied through a main laid a number of years ago, when the territory was sparsely settled, enables me to present Exhibit 3. Comment on this record is unnecessary. After securing this diagram I installed a governor and set it at eleven tenths. Exhibit 4 shows what happened. I am now doing for myself, and at my own expense, that which the gas company fails to do for me. This governor, therefore, renders me almost entirely independent of the gas company; and, in order to demonstrate more clearly to what degree this independence extends, the gauge has been allowed to run for forty-eight hours without changing the card, thus super-imposing the record of the second day upon that of the first. Note how closely the readings for the two days agree. The governor is a protection against excess of pressure only; if the street pressure falls below eleven tenths—the point at which my governor is set—automatic regulation ceases, and my gas simply becomes subject to practically the same variations as exist on the main. Happily, the latter condition is infrequently realized in our neighborhood. No argument is needed to prove how successfully a governing device of this nature can cope with the trouble indicated by Exhibit 1, or how utterly inadequate it is to afford relief from the evil depicted in Exhibit 2Increased pressure is the only remedy for the latter.

The gas company does not recommend the use of these house-to-house governors—presumably because such a recommendation would be in effect an admission that the service as now maintained by the company is not satisfactory.Indeed, the less enlightened officials—and it is these, unfortunately, with whom the consumer has generally to deal—positively and unreasoningly condemn all such regulating devices.In spite of this, there exist to-day several gas-reduction companies, whose sole occupation consists in exploiting various gas-pressure-regulating appliances, which are rented to consumers for a certain percentage of the monthly saving in the gas bills which their use effects.

It would appear to be a self-evident proposition that when one pays for gas delivered at his meter he is entitled to receive that gas under such a pressure as will afford the most satisfactory service.This pressure is found to be one inch.Making due allowance for reasonable fluctuations of a few tenths above the normal, any further departure from the standard may be taken as a sure indication of a disinclination on the part of the company to meet the expense of new pipes and regulating apparatus.The time is not far distant when the public will demand, not cheaper gas nor better gas, but a more satisfactory service.But before condemning the gas company one must look to his house piping.The company’s responsibility ends just inside the meter, and from that point the consumer must provide satisfactory appliances, giving the same attention to the gas pipes as he gives to the plumbing.This is seldom done and the company is frequently blamed for the neglect of the householder.

The gas engineer, steering between the Scylla of ‘poor’ gas and the Charybdis of excessive pressures, finds himself still ‘dangerous in the rapids’ of financial expenditure.At present he is doing the best he can with the money doled out to him by the management.

It will be observed that up to the present point the gas meter itself has played no part in the discussion.The meter, although greatly maligned, is in reality an eminently satisfactory piece of mechanism. Concerning this apparatus many erroneous notions prevail. One of these is that a householder may burn thousands of feet of gas without cost to himself, provided he keeps the company in blissful ignorance of the employment of gas for heating purposes upon his premises. The demonstration of the falsity of this idea lies within the reach of any one who will take the trouble to read his own meter on those days on which the company’s indexer pays his monthly visits.

Figs.1, 2 and 3 represent different states of the index usually employed on the three, five and ten light meters, the sizes commonly found in our dwellings. The smaller dial, placed centrally above the other, is known as the ‘proving dial,’ and, being used merely for testing purposes, is not considered in reading the gas consumption. Although the index dials vary in nomenclature as well as in number, it is generally safe to consider that if the name is placed above the dial a complete revolution of the pointer is required to register the amount of gas indicated by the name; whereas if the name is placed below the dial each numbered division of the dial represents the amount corresponding to the name. If doubt still exists as to the value of each division of the lowest or right-hand dial, remember that no meter index is designed to read less than one hundred cubic feet for each division of the circle.

After one has indexed his own meter for a month or two he is in a position to begin checking the bills presented.The ‘present state of meter’ and the ‘previous state of meter’ are always specified, and the mere subtraction of the former from the latter gives the consumption.This is not invariably the case, however.After a meter has registered its maximum reading—100,000 in the smaller sizes—it passes over the zero point and begins to build up a new record.This happens at intervals as long as the apparatus is kept in service. Before me lies a bill giving the ‘present state’ as 1,700 and the ‘previous state’ as 96,300. Since the meter was continuously employed, it must have registered up to 100,000, so that it registered 3,700 cubic feet on the old score before recording 1,700 cubic feet on the new. Consequently, adding 1,700 to the difference between ‘previous state’ and the highest possible reading gives 5,400 cubic feet—the amount consumed during the month. By reading one’s own meter the detection of any error on the part of the indexer or of the clerical force at the gas office becomes possible. Errors of this nature are of rare occurrence, as those who have adopted this plan of checking gas bills will testify. The responsibility for excessive bills is thus taken from the gas employees and thrown entirely upon the gas-registering mechanism itself. Those people, then, who chuckle furtively over the fact that the gas company has not ‘caught on’ to the surreptitious use of gas ranges are either the fortunate possessors of ‘slow’ meters or are deluding themselves as to the amount of gas which they actually consume.

Fig.4 is a photograph of the common dry meter, with the front, back, top and left side removed. It is called a ‘dry’ meter to distinguish it from those meters, having little vogue in this country, which employ a liquid in place of a valve motion. The apparatus shown consists of a case divided into three compartments by a horizontal partition one fourth of the way down from the top, and by a vertical partition centrally placed and extending upward from the bottom of the casing to the horizontal partition. The upper compartment contains the registering mechanism and a small valve chamber, the latter corresponding to the steam chest of an engine. In each of the lower compartments is a metal disk attached to the central partition by well-oiled flexible leathers, each disk, leather and the partition forming a bellows. As in a locomotive, the meter really consists of two separate mechanisms, set to operate out of phase and avoid dead centers.

Considering one mechanism only, recourse may be had to a diagrammatic representation of the action (Fig.5). Gas entering the inlet passes into the valve chamber. Here an ordinary D-slide-valve closes two of the openings, leaving a third through which the gas may flow into the bellows or inner compartment. The bellows expands, gradually filling the outer compartment, and forcing the gas out under the valve into the outlet pipe, as indicated by the arrows. When the bellows is fully distended the valve shifts into the position shown in Fig.6, admitting the inflowing gas to the outer compartment and collapsing the bellows, whose contents are forced into the outlet pipe by the paths traced by the arrows.

Thus, it will be observed, the meter is a volume measurer pure and simple, measuring cubic feet with as much deliberation as is required to deal water out of a cask by means of a pint dipper. Its percentage of error is the same at all pressures and under all loads within its capacity, and it measures cubic feet of gas regardless of whether that gas be expanded or compressed.

And so we are obliged to realize, as another fallacy is exposed, that the meter does not spin around most energetically under the higher pressures, cheerfully and accommodatingly serving its masters by adding a mythical cubic foot or two to the count at each revolution.

It remains, then, to consider the error of the meter.The custom is, in New York at least, not to set a meter that registers fast—that registers a greater volume of gas than actually passes through it.If it is found to be slow, however, and not more than three per cent., it is allowed to go out.As a result, the meter, when first placed, always favors the consumer, sometimes to the extent of recording only ninety-seven feet of gas for each one hundred feet actually passed.Owing to the aging of the mechanism and the drying out of the leathers, there exists a tendency to increase the registry for each cubic foot passed.In this way a slow meter may become a fast meter after a period of active service.From the meager data at my disposal, it would appear that every meter should be called in for a thorough overhauling and readjustment at periodic intervals of from three to five years.

Assuming that there are several million gas meters in Greater New York alone, it is but natural to expect that out of this vast number, in spite of any reasonable care that may have been exercised in their adjustment originally, many will be found subsequently to be defective—some because of mechanical injury, some through sheer old age.Unfortunately, it is not possible as yet to obtain a convincingly large array of figures; but in the Borough of Brooklyn, where there are in service nearly a quarter of a million meters, and where complaints against them have been studiously encouraged by the authorities, one hundred and eighty-seven meters have been carefully tested.Here are the results:

When one remembers that these one hundred and eighty-seven meters are presumably the worst of their kind, having been put in evidence by a naturally suspicious public, it is but fair to assume that the figures overrate rather than underestimate the errors of the average gas meter. Quoting from The Progressive Age, a journal devoted largely to the interests of the gas industry: “The meters made to-day will remain a long while in service before they begin to register incorrectly, and when we consider the dampness, extremes of temperature and hard usage they receive as they are transferred from cellar to attic, from among the dust, cobwebs and litter of a basement closet to the corner shelf of some coal cellar, to be the playground of rats, spiders and cockroaches, to be drenched in summer by sweating or leaky water pipes and wear a venerable beard of icicles in winter—to be, in fact, the worst-used machine about a gas plant—we can not fail but express surprise that it registers at all correctly.”

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THE SUN’S DESTINATION.
By Professor HAROLD JACOBY,
COLUMBIA UNIVERSITY.

Three generations of men have come and gone since the Marquis de Laplace stood before the Academy of France and gave his demonstration of the permanent stability of our solar system. There was one significant fault in Newton’s superbly simple conception of an eternal law governing the world in which we live. The labors of mathematicians following him had shown that the planets must trace out paths in space whose form could be determined in advance with unerring certainty by the aid of Newton’s law of gravitation. But they proved just as conclusively that these planetary orbits, as they are called, could not maintain indefinitely the same shapes or positions. Slow indeed might be the changes they were destined to undergo; slow, but sure, with that sureness belonging to celestial science alone. And so men asked: Has this magnificent solar system been built upon a scale so grand, been put in operation subject to a law sublime in its very simplicity, only to change and change until at length it shall lose every semblance of its former self, and end perhaps in chaos or extinction?

Laplace was able to answer confidently: No.Nor was his answer couched in the enthusiastic language of unbalanced theorists who work by the aid of imagination alone.Based upon the irrefragable logic of correct mathematical reasoning, and clad in the sober garb of mathematical formulæ, his results carried conviction to men of science the world over.So was it demonstrated that changes in our solar system are surely at work, and shall continue for nearly countless ages; yet just as surely will they be reversed at last, and the system will tend to return again to its original form and condition.The objection that the Newtonian law meant ultimate dissolution of the world was thus destroyed by Laplace.From that day forward, the law of gravitation has been accepted as holding sway over all phenomena visible within our planetary world.

The intricacies of our own solar system being thus illumined, the restless activity of the human intellect was stimulated to search beyond for new problems and new mysteries.Even more fascinating than the movements of our sun and planets are all those questions that relate to the clustered stellar congeries hanging suspended within the deep blue vault of night.Does the same law of gravitation cast its magic spell over that hazy cloud of Pleiads, binding them, like ourselves, with bonds indissoluble? Who shall answer, yes or no? We can only say that astronomers have as yet but stepped upon the threshold of the universe, and fixed the telescope’s great eye upon that which is within.

Let us then begin by reminding the reader what is meant by that Newtonian law of gravitation.It appears all things possess the remarkable property of attracting or pulling each other.Newton declared that all substances, solid, liquid or even gaseous, from the massive cliff of rock down to the invisible air—all matter can no more help pulling than it can help existing.His law further formulates certain conditions governing the manner in which this gravitational attraction is exerted; but these are mere matters of detail; interest centers about the mysterious fact of attraction itself.How can one thing pull another with no connecting link through which the pull can act?Just here we touch the point that has never yet been explained.Nature withholds from science her ultimate secrets.They that have pondered longest, that have descended farthest of all men into the clear well of knowledge, have done so but to sound the depths beyond, never touching bottom.

This inability of ours to give a good physical explanation of gravitation has led numerous paradoxers to doubt or even deny that there is any such thing.But fortunately we have a simple laboratory experiment that helps us.Unexplained it may ever remain, but that there can be attraction between physical objects connected by no visible link is proved by the behavior of an ordinary magnet.Place a small piece of steel or iron near a magnetized bar, and it will at once be so strongly attracted that it will actually fly to the magnet.Any one who has seen this simple experiment can never again deny the possibility at least of the law of attraction as stated by Newton.Its possibility once admitted, the fact that it can predict the motions of all the planets, even shown to the minutest details, transforms the possibility of its birth into a certainty as strong as any human certainty can ever be.

But this demonstration of Newton’s law is limited strictly to the solar system itself.We may indeed reason by analogy, and take for granted that a law which holds within our immediate neighborhood is extremely likely to be true also of the entire visible universe.But men of science are loath to reason thus; and hence the fascination of researches in cosmic astronomy.Analogy points out the path.The astronomer is not slow to follow; but he seeks ever to establish upon incontrovertible evidence those truths which at first only his daring imagination had led him to half suspect.If we are to extend the law of gravitation to the utmost, we must be careful to consider the law itself in its most complete form. A heavenly body like the sun is often said to govern the motions of its family of planets; but such a statement is not strictly accurate. The governing body is no despot; ’tis an abject slave of law and order, as much as the tiniest of attendant planets. The action of gravitation is mutual, and no cosmic body can attract another without being itself in turn subject to that other’s gravitational action. If there were in our solar system but two bodies, sun and planet, we should find each one pursuing a path in space under the influence of the other’s attraction. These two paths or orbits would be oval, and if the sun and planet were equally massive, the orbits would be exactly alike, both in shape and size. But if the sun were far larger than the planet, the orbits would still be similar in form, but the one traversed by the larger body would be small. For it is not reasonable to expect a little planet to keep the big sun moving with a velocity as great as that derived by itself from the attraction of the larger orb. Whenever the preponderance of the larger body is extremely great, its orbit will be correspondingly insignificant in size. This is in fact the case with our own sun. So massive is it in comparison with the planets, that the orbit is too small to reveal its actual existence without the aid of our most refined instruments. The path traced out by the sun’s center would not fill a space as large as the sun’s own bulk. Nevertheless, true orbital motion is there.

So we may conclude that as a necessary consequence of the law of gravitation every object within the solar system is in motion.To say that planets revolve about the sun is to neglect as unimportant the small orbit of the sun itself.This may be sufficiently accurate for ordinary purposes; but it is unquestionably necessary to neglect no factor, however small, if we propose to extend our reasoning to a consideration of the stellar universe.For we shall then have to deal with systems in which the planets are of a size comparable with the sun; and in such systems all the orbits will also be of comparatively equal importance.

Mathematical analysis has derived another fact from discussion of the law of gravitation which perhaps transcends in simple grandeur everything we have as yet mentioned.It matters not how great may be the number of massive orbs threading their countless interlacing curved paths in space, there yet must be in every cosmic system one single point immovable.This point is called the Center of Gravity.If it should so happen that in the beginning of things, some particle of matter were situated at this center, then would that atom ever remain unmoved and imperturbable throughout all the successive vicissitudes of cosmic evolution.It is doubtful whether the mind of man can form a conception of anything grander than such an immovable atom within the mysterious intricacies of cosmic motion.

But in general, we can not suppose that the centers of gravity in the various stellar systems are really occupied by actual physical bodies. The center may be a mere mathematical point in space, situated among the several bodies composing the system, but nevertheless endowed with the same remarkable property of relative immobility.

Having thus defined the center of gravity in its relation to the constituent parts of any cosmic system, we can pass easily to its characteristic properties in connection with the inter-relation of stellar systems with one another.It can be proved mathematically that our solar system will pull upon distant stars just as though the sun and all the planets were concentrated into one vast sphere having its center in the center of gravity of the whole.It is this property of the center of gravity which makes it preëminently important in cosmic researches.For, while we know that center to be at rest relatively to all the planets in the system, it may, nevertheless, in its quality as a sort of concentrated essence of them all, be moving swiftly through space under the pull of distant stars.In that case, the attendant bodies will go with it—but they will pursue their evolutions within the system, all unconscious that the center of gravity is carrying them on a far wider circuit.

What is the nature of that circuit?This question has been for many years the subject of earnest study by the clearest minds among astronomers.The greatest difficulty in the way is the comparatively brief period during which men have been able to make astronomical observations of precision.Space and time are two conceptions that transcend the powers of definition possessed by any man.But we can at least form a notion of how vast is the extent of time, if we remember that the period covered by man’s written records is registered but as a single moment upon the great revolving dial of heaven’s dome.One hundred and fifty years have elapsed since James Bradley built the foundations of sidereal astronomy upon his masterly series of star-observations at the Royal Observatory of Greenwich, in England.Yet so slowly do the movements of the stars unroll themselves upon the firmament, that even to this day no one of them has been seen by men to trace out more than an infinitesimal fraction of its destined path through the voids of space.

Travelers upon a railroad can not tell at any given moment whether they are moving in a straight line, or whether the train is turning upon some curve of huge size.The St.Gothard railway has several so-called ‘corkscrew’ tunnels, within which the rails make a complete turn in a spiral, the train finally emerging from the tunnel at a point almost vertically over the entrance.In this way the train is lifted to a higher level.Passengers are wont to amuse themselves while in these tunnels by watching the needle of an ordinary pocket compass.This needle, of course, always points to the north; and as the train turns upon its curve, the needle will make a complete revolution. But the passenger could not know without the compass that the train was not moving in a perfectly straight line. Just so we passengers on the earth are unaware of the kind of path we are traversing, until, like the compass, the astronomer’s instruments shall reveal to us the truth.

But as we have seen, astronomical observations of precision have not as yet extended through a period of time corresponding to the few minutes during which the St.Gothard traveler watches the compass.We are still in the dark, and do not know as yet whether mankind shall last long enough upon the earth to see the compass needle make its revolution.We are compelled to believe that the motion in space of our sun is progressing upon a curved path; but so far as precise observations allow us to speak, we can but say that we have as yet moved through an infinitesimal element only of that mighty curve.However, we know the point upon the sky towards which this tiny element of our path is directed, and we have an approximate knowledge of the speed at which we move.

More than a century ago Sir William Herschel was able to fix roughly what we call the Apex of the sun’s way in space, or the point among the stars towards which that way is for the moment directed.We say for the moment, but we mean that moment of which Bradley saw the beginning in 1750, and upon whose end no man of those now living shall ever look.Herschel found that a comparison of old stellar observations seemed to indicate that the stars in a certain part of the sky were opening out, as it were, and that the constellations in the opposite part of the heavens seemed to be drawing in, or becoming smaller.There can be but one reasonable explanation of this.We must be moving towards that part of the sky where the stars are separating.Just so a man watching a regiment of soldiers approaching, will see at first only a confused body of men.But as they come nearer the individual soldiers will seem to separate, until at length each one is seen distinct from all the others.

Herschel fixed the position of the apex at a point in the constellation Hercules.The most recent investigations of Newcomb, published only a few months ago, have, on the whole, verified Herschel’s conclusions.With the intuitive power of rare genius, Herschel had been able to sift truth out of error.The observational data at his disposal would now be called rude, but they disclosed to the scrutiny of his acute understanding the germ of truth that was in them.Later investigators have increased the precision of our knowledge, until we can now say that the present direction of the solar motion is known within very narrow limits.A tiny circle might be drawn on the sky, to which an astronomer might point his hand and say: Yonder little circle contains the goal towards which the sun and planets are hastening to-day. Even the speed of this motion has been subjected to measurement, and found to be about ten miles per second.

The objective point and the rate of motion thus stated, exact science holds her peace.Here genuine knowledge stops; and we can proceed further only by the aid of that imagination which men of science need to curb at every moment.But let no one think that the sun will ever reach the so-called apex.To do so would mean cosmic motion upon a straight line, while every consideration of celestial mechanics points to motion upon a curve.When shall we turn sufficiently upon that curve to detect its bending?’Tis a problem we must leave as a rich heritage to later generations that are to follow us.The visionary theorist’s notion of a great central sun, controlling our own sun’s way in space, must be dismissed as far too daring.But for such a central sun we may substitute a central center of gravity belonging to a great system of which our sun is but an insignificant member.Then we reach a conception that has lost nothing in the grandeur of its simplicity, and is yet in accord with the probabilities of sober mechanical science.We cease to be a lonely world, and stretch out the bonds of a common relationship to yonder stars within the firmament.

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CORRESPONDENCE.

COMPARATIVE LONGEVITY AND GREATNESS.

Whether or not great men are favored by an increase of years above those allotted to more ordinary mortals has long been a question of interest, and has acquired a special importance in connection with the study of the natural history of men of genius, and the discussions of the possible relation of greatness to degeneracy and to insanity.Questions of this type can only be decided on the basis of extensive and carefully collected data, which unfortunately it is difficult and at times impossible to collect or to find.It is therefore natural that such evidence as seems to exist and to carry with it some degree of logical force should be brought forward in proof of a claim which on general principles is both pleasing and plausible.Of this type is the problem of the relation between longevity and greatness, and of this type is the evidence now and then brought forward to substantiate the belief that great men are, as regards longevity, an unusually favored class.

The most recent presentation of the topic (by Mr. Thayer in the Forum, February, 1900) collects a list of some five hundred prominent men and women of the nineteenth century and finds that these persons lived on an average sixty-eight years and eight months; that is, nearly thirty years longer than the population as a whole.And on the basis of this conclusion the writer combats the notion that nineteenth-century men of genius or of eminence exhibit signs of degeneracy, because longevity and the ability to do sustained work for a large number of years is in itself a sign of unusual vitality and vigor.As these conclusions are apt to be extensively quoted, and as they seem to me founded upon a serious fallacy, I shall attempt to present as simply as possible the nature of the desired evidence which alone could prove that great men are longer lived than others, and to show that the evidence thus far presented is inadequate to support the conclusion which has been drawn.Mr. Thayer is not the first one to present the average age at death of a number of eminent persons as evidence of unusual longevity.In an article which was reprinted in the Popular Science Monthly for May, 1884, the average age at death of 1,741 astronomers was given, and found to be sixty-four years and three months; and on the basis of this fact the author claimed that astronomers enjoyed unusual longevity.In a brief contribution published in Science, October 1, 1886 (and republished in Nature, November 4, 1886), I called attention to the fallacy inherent in such conclusions, and also presented some new contributions to the question of the longevity of great men.The materials of that article I shall utilize in the present discussion.

To reach the kernel of the matter at once, the reader must note that the fallacy consists in neglecting to consider that in dealing with astronomers or with great men, or with persons of eminence of the nineteenth century, one is dealing with a group which is already carefully selected, and the selection of which inevitably involves the attainment of a certain ageThe result is that we are not dealing with average persons as regards longevity, but with persons who in the very nature of things have already reached a certain period of maturity.No one can become a poet, or a novelist, or a painter, or a philosopher, or a commander or a statesman unless he lives at least a sufficient number of years to acquire the development of an adult, and to have the opportunity of developing his abilities and distinguishing himself. If great men were great from their infancy, and if we had the means of ascertaining this fact, then, and only then, would the method used be correct.

It is ordinarily stated that the average duration of life is somewhere between thirty-three and forty years, and Mr. Thayer considers that in the present century it has moved forward towards the latter figure. What this means is that if we were to keep a record of the age at death of all Americans who are to be born within the first ten years of the coming century, we should find that their average age at death would be some thirty odd years. But this number can by no means be used as a standard with which to compare the average age at death of men of distinction, or indeed of any other class of men selected according to a standard which involves on their part the attainment of mature years. If we were investigating the longevity of twins, or of persons with supernumerary toes, or indeed of persons possessing any quality which one could detect in new-born infants, and if we could determine the average life-period of this class of persons and find that it markedly exceeded the average of the entire community, we should be entitled to conclude that twins, or persons who have supernumerary toes, are blessed with a greater longevity than the average man. But so long as men who are to acquire distinction bear no traces upon them of this power until they exhibit their powers and actually gain distinction, it is obvious that we are concerned with their longevity only from that moment when they have entered, or have become promising candidates for that class of selected individuals whose longevity we are investigating. Proceeding on this basis, I tried to determine the age at which, on the average, men of genius had accomplished a work sufficient to entitle them to be so denominated. This investigation was instigated by Mr. C. S. Peirce, then in charge of courses in logic at the Johns Hopkins University. Under his leadership a small company, of whom I was one, proposed to study certain traits of great men, and for this purpose we tried to select the three hundred greatest men of all times. The work was never carried on to completion, so that the final selection of the names, and particularly their use in the present connection, must rest on my sole responsibility. I mention these facts mainly to indicate the general representative character of the list which I used. I take from my previously published article the following essential facts: Omitting all doubtful names, about two hundred and fifty names remain, presenting a list which most persons would agree to be fairly representative of the greatest men of all times. Of these again I selected at random those about whom it was easiest to fix the age at which they had done work which would entitle them to a place on this list, or work which almost inevitably led to such distinction. It is a date about midway between the first important work and the greatest work. The average of over sixty such ages is thirty-seven years; which means that, on the average, a man must be thirty-seven years old in order to be a candidate for a place on this list. The real question, then, is, How does the longevity of this select class of thirty-seven-year-old men compare with that of more ordinary individuals? The answer is given by the expectation of life at thirty-seven years, which is twenty-nine years, making the average age at death sixty-six years. And this is precisely the age at death of these sixty great men; showing that, as a class (for these sixty may be considered a fair sample) great men are not distinguished by longevity from other men.

It will thus be seen that my own conclusion is entirely opposed to that of Mr. Thayer.But this opposition rests not upon a difference of data, but upon a difference of logic. To my mind the enumeration of ages at death of any number of great men cannot prove unusual longevity unless we take into consideration and can determine the number of years which, on the average, a person must have lived in order to become a candidate for the class under consideration. The comparison with the average age (that is, the period of about thirty-five or more years) is not only false; it is essentially absurd; for it would become possible only if we had among poets, and painters, and musicians, and historians, and scientists, and generals a goodly number who succumbed to the diseases of early infancy, or to some of the ills that juvenile flesh is heir to.

It may be well to illustrate at this point just what conclusions may be drawn from the data which Mr. Thayer and other writers have presented.The first conclusion is that it takes a considerable length of time to become eminent—on the whole a very natural and comprehensible statement.And with regard to the astronomers previously mentioned it is even possible to go farther; for these astronomers have been divided into four degrees of eminence, and it is found that astronomers of the first rank are longer-lived than those of the second, and these in turn are longer-lived than those of the third class, and these in turn are longer-lived than those of the fourth class.Therefore, the author concludes, the greatest astronomers have been most favored with length of years, and adds, as practical advice, “Be an astronomer and live long.”Now, of course, the true conclusion is that it takes longer to accomplish work which will entitle one to pre-eminence amongst astronomers than to do work which will only achieve moderate distinction.And the practical conclusion would read, “Live long enough to become great as an astronomer and you will probably, with the ordinary expectation of life, have a good chance of completing your three score and ten.”In the same way Mr. Thayer’s list of nineteenth-century celebrities might fairly be said to suggest the conclusion that in the present century one must already have labored for a goodly number of years before one’s name would be selected by a student of the longevity of great men.So far, then, these facts have an interesting interpretation.

It may also be worth while to note that if all the men whose longevity is to be compared are of a comparable class (that is, comparable with regard to the attainment of years which they assume), then the longevity of different groups of celebrities may be compared with one another.Thus it is possible to compare the longevity of musicians with that of scientists (of about equal eminence), and according to Mr. Thayer’s lists the scientists lived ten years longer than the musicians.The same conclusion appears in my own study, in which the scientists appear amongst the longest-lived, and the musicians amongst the shortest-lived men of genius.This conclusion must not be pressed too far, but in a general way it certainly is a bit of evidence worthy of consideration as proving that distinguished scientists live longer than distinguished musicians.It would be wrong to draw rigid conclusions from comparisons of small groups, and therefore it is better to contrast the average age at death of the various men studied in as large and as general classes as possible; e.g., as men of thought, men of feeling and men of action.All of the studies with which I am acquainted point to the conclusion that men of thought live longer than those who achieve distinction through unusual qualities of their emotional natures.

We may now approach the question, whether or not it is possible to prove that the men of distinction of the nineteenth century are longer-lived or shorter-lived than their every-day contemporaries.It would be possible to do this had we statistics of the age at death of the various professions; and again, had we these deaths classed according to the distinction which the individuals attained. In addition to this it would be necessary to ascertain (with some rough approximation, as I have attempted to do with regard to the greatest men of all times) the age at which they had accomplished sufficient work to entitle them to be enrolled in their special class. To take concrete instances, let us suppose that we wish to investigate the longevity of American lawyers. Now to be a lawyer in name only requires the candidate to have lived twenty-one years, and the average number of years which the average person of twenty-one years of age will continue to live is about forty; so that the mere fact that a man is a lawyer would bring his average age at death up to sixty-one years. I find in Mulhall’s Dictionary of Statistics the statement made that the lawyers of Frankfurt die at the average age of fifty-four years, while merchants live to be fifty-seven years old. I know nothing about the authority of these figures, and am using them for illustration only. Assuming all the data to be correct (and twenty-one seems not too high an age for this purpose), this would seem to suggest that the ordinary lawyer of Frankfurt is not favored with abundance of years. In passing, it is interesting to note that these Frankfurt statistics of lawyers and merchants and other classes show a uniformly lower age at death than those of the more eminent representatives of their professions. This is just what we should expect; for to be included in the one group one must have lived only long enough to prepare and establish one’s self as a lawyer or as a merchant; while for the other group one must in addition have had opportunity to cultivate one’s ability to a riper fruitage, and in a keen, and often long competition gain public recognition. It thus follows that the average longevity of the most distinguished lawyers will be greater than that of ordinary lawyers, because it takes longer to enter the more select class. But this argument, like many others, should not be pressed too far; innate ability may accomplish in a brief period what for more moderate powers is the work of many years. Nonetheless, in the study of comparative longevity it is the average that is significant; and it is the fluctuation of the average that we aim to discover. Thus, in the investigation of the longevity of an unwholesome occupation, such as would be accepted by a life insurance company only at special rates, we should expect to find the age at death of such individuals less than that of other classes involving an equal period of apprenticeship; but, of course, not less than that of the ‘population as a whole.’ And, to continue with the main argument, if we wish to investigate the longevity of shoemakers we should again have to decide upon some age at which on the average a person has probably already acquired the dexterity requisite to be a shoemaker. Even if we fix this so low as ten years, at which time the expectation of life is forty-eight years, it would bring the average age at death of shoemakers to fifty-eight years. It has thus become extremely obvious that if we compared these ages at death with the average life-period it would be just as easy to prove that lawyers and shoemakers and merchants enjoy exceptional longevity, as to prove that great men do. The average longevity is low because of the very large infant mortality, which enters into the composition of this average. When once the first ten years of life are passed the further expectation of life increases quite slowly. Roughly speaking, for every ten years between ten and fifty years the added expectation of life is but three years for each decade. We therefore see that in the very nature of things no one class of adults can possibly live as much as thirty years longer than ‘the population as a whole.’ The differences with which we are dealing are differences of a finer order, of a small number of years, and being slight differences, must be substantiated by a relatively large number of cases; the cases, moreover, must be collected in a wholly unobjectionable manner; that is, in a manner in which the principle of selection bears no influence upon the longevity. To my knowledge adequate statistics which exhibit the relative longevity of different classes do not exist, and they certainly do not exist with regard to great men. We may therefore conclude that the facts which have thus far been collected are not opposed to the conclusion that great men enjoy favorable longevity, but they certainly have not established or contributed to the establishment of this fact. While it is not impossible to collect material which may serve as corroborative evidence of the longevity of great men, it seems probable that we must be content with evidence of a far inferior character.

Although I regard Mr. Thayer’s argument concerning longevity as entirely fallacious, I find myself in sympathy with his main contention.It seems to me that much of the evidence which has been brought forward to assimilate greatness with degeneracy is of questionable value and that the logical force of such evidence has been very much overrated.That genius and insanity are related is probably capable not of demonstration, but of a moderate degree of substantiation; but this evidence must be both judiciously collected and judiciously interpreted.It cannot be presented in a popular form without subjecting it to the danger of serious and harmful misrepresentation.In the same way the question of degeneracy and its bearing upon modern life has been frequently misstated, so that statements of protests such as Mr. Thayer offers are both opportune and likely to have a wholesome effect.But the present concern is only with the relation of longevity to greatness as an indication of the absence of degeneracy.That long life is inconsistent with a general degeneracy may be admitted; but that great men exhibit this quality to any unusual degree has certainly not been proven.

Joseph Jastrow.
University of Wisconsin.

SCHOOL REFORM.

School teachers and educational reformers undoubtedly take themselves and their ideas too seriously. Accordingly one rejoices to see an eminent man put his own affairs aside for a moment and discuss educational theories in a humorous vein. Even ridicule should be welcomed if it can relieve the sombre earnestness of the educational platform and press. Professor Münsterberg, in the Atlantic Monthly for May, has done pedagogy this service by subjecting the elective system and professional training for high-school teachers to considerable good-natured ridicule. His article is so readable that one is led to suppose that it was written to be read, not to be believed. Moreover, Professor Münsterberg’s eminence as a psychologist should not be taken as a sign that he thinks he knows aught of education. He has himself warned us against the illusion that psychology can derive truth about teaching, or that the psychologist can inform the teacher or anything of value. It may be that the wholesome matters of fact, as well as the brilliant imaginative criticism of this article are only play. The very strenuousness of the teacher’s nature, however, will probably lead him to try to extract some new gospel of reform from Professor Münsterberg’s lightest pleasantry; consequently it seems wise to consider the article as a serious argument and provide a possible antidote for it.

Professor Münsterberg contends that it is unwise to give high-school teachers special professional education apart from knowledge of the subjects which they are to teach; that it is folly to replace a prescribed course of study by an elective system; that the salvation of our schools depends upon the scholarship of the teachers and the attitude of parents.As the reformers agree heartily with this last claim (unless it is made an exclusive aim), and as its meaning is so vague that almost anything can be urged as a corrolary to it, it may be dismissed. The first two contentions are about concrete matters of educational practice which need to be thought over. If professional preparation is a waste of time, there is every reason why we should omit it; if a prescribed course of study is better for the boys and girls, we can conscientiously lessen the expense and labor of administration in many schools.

The argument on the first point is, briefly, that Professor Münsterberg’s teachers were good teachers and that they had no notion of even the vocabulary of educational theories.But obviously that may not have been the secret of their success.A majority of the high-school teachers in New England have had no professional training, yet no one has observed that they are superior to those of their class who have.The argument is really a bare assertion of an unverified guess.It is the hap-hazard opinion of an eminent psychologist who perchance is trying to furnish evidence of his previous theory that psychology does not give one knowledge about teaching.It is worth while to note here a certain interesting aspect of human nature.Training in one sphere of intellectual activity need not bring ability in other spheres.The habit and power of observation or reasoning acquired in connection with chemistry need not make a man a good observer or reasoner in politics or philology.So we should not be surprised that a man eminent for his scientific habits as a psychologist should, on a question in another field, offer imaginative hypotheses without an attempt to verify them, or to collect pertinent evidence or to eliminate factors outside those he discusses.We may be allowed to feel sorry.If a scientist wishes to really clear up the question of the value of professional training, why does he not find representatives of the classes, ‘teachers with professional training’ and ‘teachers their equals in other respects, who have replaced the effort after professional training by equal effort after further scholarship,’ and compare the work of the two classes?If other factors enter to disturb such an investigation, why not carefully look at the facts to ascertain their influence?Until he does so his dicta will stand as mere opinions.It would be a blessing if scientific men would use the weight of their reputations, not to bolster up their after-dinner opinions about things in general, but to teach the public scientific methods of studying them.

Apart from the danger of offering pedagogy an unproved opinion as a fact, it seems poor economy to leave a question in such shape that only the opinion of another eminent man on the opposite side is required to destroy the result you have attained.Precisely this has occurred in the case of Professor Münsterberg’s contributions to educational discussion two years ago.Another eminent man, Professor Dewey, has recently squarely denied what Professor Münsterberg affirmed.It only remains for some equally eminent German professor to rise and declare that his teachers were bad and that they had no professional training, or that his teachers were good and had it, and Professor Münsterberg’s effect is neutralized.

Professor Münsterberg’s argument against the elective system is more complex.He regards the elective system as partly a concession to the obvious need of fitting young people earlier for their occupations in life and partly an attempt to use the likes and dislikes of children as a guide to what is good for them.This is a very narrow view.The elective system has been in part the result of the progress of science and the consequent conviction that the scientific study of things and human affairs should be a part of one’s education.The elective system furnished a compromise by which such studies found a place in the college and school curricula.If the student is left to choose among them, instead of having a new prescribed course made out on the basis of modern views of life’s needs, it is partly because they are more easily introduced and retained as electives and partly because there is no agreement as to which studies will be the best to prescribe.

The idea that reformers desire to have a course containing studies good for children and studies not good for them and to trust the scholars’ likes and dislikes to guide them to the former, is absurd.Whether they are right in assuming that what is best for one boy may not be best for another, that his teachers and parents can help him to pick out a course of study better for him than any inflexible course prescribed for all can be, is a question of importance, but one which Professor Münsterberg does not try to answer.Instead, he tells us about his gratitude to his parents and teachers for never letting him neglect his steady toil at prescribed Greek for the pursuits which he himself elected out of school, such as electrical engineering, botany, novel-writing, reading Arabic, writing books on the prehistoric anthropology of West Prussia, etc., etc. Now, this confession about his early life absolves us from paying any further attention to his experience as a lesson to our high-school youths.The youth Münsterberg and the average high-school student do not belong in the same class.For he was evidently an eminent boy as he is an eminent man.We must admit, however, that the rigorous discipline afforded by the prescribed Latin and Greek is evidenced in the present stern moral sense of the professor, who is willing to abandon his chosen and favorite pursuit, laboratory experimentation, and at the call of duty give himself to the hated but necessary tasks of writing philosophical disquisitions, political discussions and articles on school reform.

X.

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SCIENTIFIC LITERATURE.

CHEMISTRY.

The general interest which has been aroused the last few years in physical chemistry is reflected in the number of books which have appeared in this department.Some of these dwell more upon the older physical chemistry, devoting but relatively little space to the later developments, while others are chiefly concerned with the newer phases of the subject.Perhaps the most satisfactory book which has appeared along this line is Walker’s ‘Introduction to Physical Chemistry’ (Macmillan).No attempt is made to exhaust the field but the subject is well covered.Especially commendable is the clearness of the book, which will render it useful to students.The non-mathematical treatment of the subject will also commend it to many who use it as an introduction to physical chemistry.A book of narrower scope is Dr. H.C.Jones’s ‘Theory of Electrolytic Dissociation and Some of Its Applications,’ from the press of the same publishers.The author gives first a short review of the development of physical chemistry up to the days of van’t Hoff, and then surveys the origin of the theory of electrolytic dissociation, its proofs and some of its applications.While making no pretense to cover the whole field of physical chemistry, the author furnishes a very readable account of the most important of the later generalizations.It is a book which should be read especially by those chemists and physicists who are working in other fields, that they may gain a fair view of the electrolytic dissociation theory written by one thoroughly competent for his task.Biologists, too, will find the latter part of the book, treating of the applications of the theory to animal and plant life, of especial interest.Dr. Jones, with S.H.King, has also translated Biltz on ‘Practical Methods of Determining Molecular Weights.’This is a successful attempt to gather together the best of the different methods of real value, and it is very satisfactorily carried out, presenting a good guide book for students.

In the production of text-books of general chemistry, there seems to be a little lull, very few books having appeared in recent months.The first part of what promises to be a somewhat original work on inorganic chemistry, by Dr. Sperber, has appeared.After the introduction on general chemical laws, the elements of the seventh group (chlorine, etc.), are first considered, and then their hydrogen compounds; the sixth group (oxygen, etc.) and its hydrogen compounds; fifth group (nitrogen, etc.), etc. The method used is purely inductive, each subject being introduced by experiments from which the underlying principles are developed.

A third edition of Elliott and Ferguson’s ‘Qualitative Analysis’ has appeared which is a considerable improvement upon the previous editions.The principal merit of this book, is in the opinion of many its greatest drawback.In clearness and minuteness of directions it is hardly equalled by any manual of qualitative analysis, and thus it is a particularly easy book for the instructor to use, especially with a large class.But this, on the other hand, cannot fail to encourage mere mechanical work on the part of the student and to discourage independence.With large classes, however, it is a difficult problem how best to cultivate individuality of work.

A little manual of ‘Analysis of White Paints,’ by G.H.Ellis, will prove of value to chemists to whom now and then paint samples are brought for analysis. It is a collection of notes by a chemist who has had much experience along this line.

In the field of applied chemistry quite a number of books have come out lately, the most useful of which is probably the seventh volume of ‘The Mineral Industry.’The field of mineral resources and industries of the world is very thoroughly surveyed, and the volume is brought as closely down to date as possible.In this respect it has a great advantage over the corresponding publication of the United States Government.Among the subjects which are treated very thoroughly in the present volume are calcium carbid, fire brick and paving brick, coal mining methods and their economic bearing, progress in the metallurgy of copper and of gold, notes on the progress of iron and steel metallurgy (by Henry M.Howe), sulfuric acid, progress in ore dressing (by Robert H.Richards).It is a book necessary to the teacher, of great value to the economist and of much interest to the general reader.The second edition of McMillan’s ‘Electro-metallurgy’ is a considerable improvement on the former edition, and is brought well down to date.The greater part of the book is devoted to the electro-deposition of metals, and is thorough and satisfactory.It is, however, unfortunate that the treatment of electro-metallurgical ore-extraction should be very inadequate, this whole subject, together with electro-refining, being confined to a single chapter of thirty pages.

Lange’s ‘Chemische-technische Untersuchungsmethoden’ is passing through its fourth edition, of which the second volume is just out.This treats of metals and metallic salts, fertilizers, fodders, explosives, matches, gas manufacture, ammonia and coal tar and inorganic colors.The book aims at exhaustive treatment, and while some subjects are in parts weak, as is naturally the case where there are many different authors, it is as a whole the best work in its field.

A book in a new line is H.and H.Ingle’s Chemistry of Fire and Fire Prevention’ (Spon and Chamberlain).The book takes its origin from lectures delivered to an audience of insurance men.After three chapters on the history and theory of combustion, various industries more or less connected with fire are taken up; coal gas, dust explosions, fuel, illuminants, explosives, oils, volatile solvents, paints and varnish making, textile manufactures, spontaneous combustion, are some of the subjects treated.The last chapter is a quite useful one on fire prevention and extinction.The book contains much useful information and should prove of very considerable value outside of the rather limited audience to which it is addressed.

ZOOLOGY.

The past few months have witnessed the publication of many important works on zoölogical subjects, and among these it may not be amiss to note first Kingsley’s ‘Text-Book of Vertebrate Zoölogy,’ since it adopts a new method, that of showing the bearing of embryology upon the morphology of vertebrates, and in turn, of morphology upon their classification.Its object is stated to be to “supplement both lectures and laboratory work, and to place in concise form the more important facts and generalizations concerning the vertebrates,” and the author has succeeded in crowding a large amount of information into the 439 pages of the work.The illustrations are numerous, and for the most part very good, comprising some figures that have appeared in other text-books and some that are the outcome of Dr. Kingsley’s own work.It is to be noted that in place of many of the standard European forms that have done morphological duty for years, we have such American types as Acanthias, Necturus, Amblystoma and Sceloporus, a change for which we are duly grateful.