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.
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.
[Illustration: MAP OF THE GARDEN.]
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.
[Illustration: THE MUSEUM.]
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.
[Illustration: IN THE FOREST.]
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.
[Illustration: THE NORTH MEADOWS.]
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.
[Illustration: THE WATERFALL.]
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.
[Illustration: IN THE HERBACEOUS PLANTATION.]
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.
[Illustration: HORTICULTURAL HOUSES.]
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.
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.