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Ralph S. (Ralph Stockman) Tarr.

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LIBRARY

OF THE

University of California.



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LABORATORY MANUAL OF PHYSICAL GEOGRAPHY






THE MACMILLAN COMPANY

NEW YORK • BOSTON • CHICAGO
ATLANTA • SAN FRANCISCO

MACMILLAN & CO., Limited

LONDON • BOMBAY • CALCUTTA
MELBOURNE

THE MACMILLAN CO. OF CANADA, Ltd.

TORONTO



(



A LABORATORY MANUAL



OF



PHYSICAL GEOGRAPHY



BY



PROFESSOR R. S. TARR and O. D. VON ENGELN

OF THE DEPARTMENT OF PHYSICAL GEOGRAPHY
AT CORNELL UNIVERSITY



FOR USE IN CONNECTION WITH A GENERAL COURSE IN

PHYSICAL GEOGRAPHY IN HIGH AND SECONDARY

SCHOOLS AND IN COLLEGES



OF THE

UNIVERSITY

OF



Nefo fgotfe
THE MACMILLAN COMPANY

.1910

All rights reserved




Copyright, 1910,
By THE MACMILLAN COMPANY.



Set up and electrotyped. Published March, 1910.



Nortoooo $resa

J. S. Cushing Co. — Berwick & Smith Co.

Norwood, Mass., U.S.A.



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PREFACE

The subject of physical geography, above all others, leads to an appreciation by the pupil
of the natural world in which he lives, and an introductory course in physical geography
should include specifically a training in observation and deduction.

In the planning and writing of this manual these fundamental concepts of the necessity
of making the outlines at once practical and usable for the teacher with only a limited
laboratory equipment, and at the same time offering to the pupil this training in observation
and deduction — in fact, compelling it — have been constantly kept in mind, and it will be
found that there is a specific purpose for each exercise and that the groups form coherent
wholes. It is the belief of the authors, moreover, that the exercises cover the whole subject
adequately, and that the order in which they are arranged will be found the best for present-
ing the subject. On both these points some teachers, for specific reasons, may take issue.
This, however, implies no criticism, either on the manual as arranged or on the teacher;
for, on the one hand, the loose-leaf construction of the manual makes it a very simple matter
for the teacher to change the order or introduce other work ; while on the other hand, the
authors feel that teachers who are progressive, capable, and enthusiastic over the subject
should be given the greatest latitude in carrying out their own ideas. The laboratory study
of physical geography has an intense human interest and affords the best possible opportunity
for the infusion of a strong teaching personality.

A number of novel ideas and methods have been incorporated in this manual, but these
new features are not to be regarded as experiments. The senior author has had over fifteen
years' experience and the junior author four in the laboratory teaching of physical geography,
and the make-up of this manual incorporates plans that have been successfully used with
classes after repeated changes and modifications to secure the best possible results.

The feature which will first attract attention is the leaving of space after each question
for the student to write the answer. This serves a double purpose. It insures the student's
following the argument of the outline and the appreciation of every point by personal obser-
vation and deduction. The work thus becomes distinctly laboratory work and not essay
writing under the delusion that laboratory work is being done. This latter condition is the
greatest fault that the authors have found in most of the laboratory note-books, from various
schools throughout the country, which have come under their inspection. In the second
place this plan very materially lightens the labor of the overworked science teacher in
inspecting the note-books of the students. There is a place for every answer and every
answer should be in its place. Any incompleteness is readily detected, as is also the correct-
ness of the student's interpretations. Furthermore, the time of the student is conserved for
the actual observations, inasmuch as there is no need for the laborious rewriting of questions
in order to make the disconnected answers coherent. There is, however, sufficient space
allowed after every exercise to permit of the insertion of other material presented by the
teacher; accordingly, the exercises may vary considerably in different localities to insure
a fuller understanding of local conditions.

Another feature which we feel sure will meet with general approval is the insertion of



201630



all maps, figures, diagrams, and tables at the exact place where they are needed. The con-
venience of this plan will make its own appeal, and needs no further amplification here. ^~

The pedagogical departure in which this manual differs most markedly from those now
in use, and which is an altogether novel feature of these outlines, is the method of presenting
the physiography of the lands. In the past, in the authors' own experience and as related
by other teachers, the map work on which this phase of the subject is necessarily based has
been most distasteful and irksome to the student. This, we believe, is due to two causes :

(1) the incoherent manner in which the various topics have customarily been treated; and

(2) the fact that these topics have never been tied on to any geography of which the student
had a previous knowledge. To illustrate what is meant, take the subject of the development
of river valleys. In the first place the student was taught that Niagara River had a young
valley, and he studied its characteristics. The Mississippi, perhaps, was next studied as an
old valley. Then there was a jump to the study of a volcanic cone, Mt. Shasta. Nowhere
any logical development of the body of the subject-matter, nor any relation between succeed-
ing exercises.

This difficulty we believe we have successfully solved. In this manual young rivers are
studied in connection with young plains, old rivers on old plains, and plains in turn are con-
sidered in successive stages in their cycle of development from young to old. The basis of
the whole study is a series of carefully selected United States Geological Survey topographic
maps, and the position of these areas the student accurately locates on a United States map,
on which, also, he plots that physiographic division of the country which has conditions simi-
lar to those shown in detail on the topographic map he is studying.

The results in our own classes have been very gratifying. The students pursue the work
with keen interest ; they gain a very clear notion of the physical geography phenomena which
the maps illustrate; moreover, they associate the typical conditions of the topographic maps
with distinct areas and regions of the United States and thus gain a clear comprehension
of the varied topographic features of their own country and of their extent and significance.
This supplies the element of human interest which has been so lacking in elementary physical
geography study in the past; and it is largely to this fact that the eager interest of the
students in the above plan of study may best be ascribed.

The sections dealing with mathematical geography and tidal phenomena have been made
very simple. These are complex subjects at best, and it is the belief of the authors that they
are of a distinctly minor importance in a course in elementary physical geography.

Emphasis should be placed on the study of the processes of erosion, transportation, and
deposition as made possible by the use of the tank and land model, or some modification of it.
Such work is of the greatest value in enabling the students to get a clear, clean-cut concept
of these processes and their results ; and it enables them to proceed intelligently with the
study of the topographic forms shown on relief maps.

A few type excursions are included, four for the fall and three for the spring. It is, of
course, not possible to write excursion outlines in detail that are suitable for widely different
localities ; hence these excursions are generalized. It is the hope and belief of the authors
that they will be found useful in many schools ; but it is confidently expected that for some
or all of these many teachers will substitute specific outlines adapted to the opportunities
of the locality.

It is our belief that if a multitude of references are given, none will be used. There-
fore we have confined ourselves in the outlines to references to Tarr's "New Physical
Geography." Here may be added the titles of several publications*which the teacher will find
valuable for reference : Professional Paper # 60, United States Geological Survey. List of the
Publications of the United States Geological Survey. These may be obtained, gratis, on



C



VI



application to the Director of the United States Geological Survey, Washington, D.C. In

Sthe list of publications the teacher will find what has been published on the home locality,
and should send for such papers as are available. Other valuable helps are : —

Johnson, Mathematical G-eography, American Book Co.

Pirsson, Rocks and Rock Minerals, Wiley & Sons.

Davis, Elementary Meteorology, Ginn & Co.

Ward, Practical Exercises in Elementary Meteorology, Ginn & Co.

Other text-books of physical geography.

Many valuable papers on methods in physical geography are printed in the Journal of
Geography (R. E. Dodge, Teachers College, Columbia University, New York City), a monthly
magazine "Devoted to the Interests of Teachers of Geography." Price, $1.00 a year.

The authors will welcome any suggestions teachers may make, and, where practicable,
insert them in future editions.

Ithaca, June 10, 1909.



Vll



c



*



#



SUGGESTIONS TO TEACHERS

A teacher's manual for use in connection with these outlines for laboratory and excur-
sion work is in preparation and will be issued shortly. In it will be found particular
suggestions in regard to each exercise, together with a list of references for supplementary
reading and hints on the use of lantern slides, models, and other material which may be
available in connection with these outlines.

In the following paragraphs are given a description and suggestions for the use of the
apparatus needed in Exercises XXII, XXIII, and XXVI. These are inserted because this
method of presentation of the subject is new, and most teachers will be unfamiliar with the
apparatus used.

EXERCISES XXII AND XXIII

The Construction and Understanding of Contour Maps

On a thorough understanding and appreciation of the significance of contour lines depends
the value of all the pupil's later study of topographic conditions as expressed by maps on
which they are used. The simplest method of teaching the meaning of contour maps, where
there are no laboratory facilities, is for the teacher to draw on the blackboard an outline
of a land surface and on it write in figures indicating elevations of different points and having
the pupils copy this and connect points of equal elevation with contour lines. This and
similar methods we have found very unsatisfactory. The apparatus and method advised
and outlined in this manual are those used with much success at Cornell University, where
they solved this problem of teaching contour maps after various other methods had been tried
with indifferent results. The apparatus is subject to several modifications. Where space
and funds are available, it will be found well worth while to install a large tank with
a crank-lifted platform as described below. This apparatus can also be used for study of
erosion and depositional processes. (See following pages devoted to such exercises.) If the
dimensions given are too large, they can readily be scaled down to meet the space conditions
of the laboratory where the apparatus is to be installed. The working drawings will make
the construction of the apparatus feasible in any localit}^ or the Geography Supply Bureau,
Ithaca, New York, will quote prices on duplications of various sizes.

Description of Large Tank and Screw-crank Platform

A large square wooden tank, made water tight, eight feet on the side and sixteen inches
deep. This tank is used to hold a body of standing water whose level may be adjusted, to
suit the requirements of the exercise, by means of a series of holes (bored in the side) fitted
with removable plugs.

A solidly built square platform five feet six inches on the side. This is intended to hold
the sand, clay, or other materials of which a land form is to be molded.

In the four corners of this platform threaded iron collars are inserted, and into these are
screwed heavy iron cranks which serve at once to support the platform and raise and lower it.
The threads on the cranks and in the collars are coarse, some ten or twelve turns to the inch.
The ends of the cranks are pivoted in loosely fitting iron sockets screwed fast to the bottom
of the outer tank.

ix



MAKING READY FOE THE EXERCISE

When this apparatus is set up, the whole platform, with its incumbent model, can be S~

rapidly raised and lowered at will, by turning the cranks simultaneously.

The materials used in building up the model are sand and clay, with enough plaster
of paris admixed (a very small quantity serves this purpose) to give the forms sufficient
firmness to stand up without slumping when immersed in water for some time. Just before
the beginning of the exercise the outer tank is filled with water, the water level being adjusted
by means of the plugs on the one side, and the platform is lifted by means of the cranks until
the water surface coincides with the level of the lowest parts of the land surface.

The drawing shows the apparatus adjusted with land form modeled ready for the class
to begin work. The square outline of the map to be constructed will then be expressed
by the square outline of the platform top. Working drawings of the apparatus are given
in the accompanying drawing.

Conduction of Exercise

To conduct the contour mapping exercise proceed as follows : After a suitable scale for
the map has been adopted, outline of the model sketched, and its salient points located, the
pupils have made a map on which the or sea-level contour is expressed by the outline
of the land form. Then a contour interval is adopted. (A one-inch interval will be found
practicable for this size model.) Next, with a pupil to operate each crank, lower the model
through the vertical distance of the contour interval. Be sure that the outflow of the tank
is sufficiently large to allow the water displaced to escape rapidly. Then the class proceeds
with the sketching of the first contour. This procedure is repeated as many times as neces-
sary to complete the map.

Where the installation of the large screw-tank apparatus is not feasible the following
modification may be used. This serves fairly well with small classes.

Instead of the platform with screw cranks and land form modeled of clay and sand a much
smaller plaster of paris model is used. This is a model after an ideal land form which the
United States Geological Survey uses in describing contour maps. (See one of the United
States Geological Survey Folios.) In connection with it a small tank of water is used, filled
to the brim. In this tank are piled a number of waterproof fiber boards of uniform thickness
and heavier than water. The plaster model is placed on this pile of fiber boards and the
water level adjusted to the edge of the modeled land area. Successive contour lines are
located by removing successive sheets of the fiber board. Otherwise the procedure is
the same. This equipment is also simple of construction, but if preferred, can be obtained
through the Geography Supply Bureau of Ithaca, New York.

EXERCISE XXVI

If the tank and land model are not available, a sand table or sink of sufficient dimensions
can be arranged to carry out this experiment.

In building up the land form use molder's sand and powdered clay in alternate layers.
Have the clay layers quite thin, one half inch on the average. Build the model so that it has
variety in topography, but give it the general surface of a plain with a somewhat steep slope
toward the front. It will be well to incline the platform. If the clay layers are not sufficiently
hard to cause waterfalls, a little plaster of paris may be added. To get good deltas the water
at the edge of the land form must not be too deep, and must remain at a uniform level.
The pupils should read through the whole exercise before the experiment is begun so that (

they will be on the alert for the various phenomena. (For further details see article by Tarr
and von Engeln, in Journal of Geography, Vol. VII, 1908, pp. 73-85.)







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XI






c







COMPLETE LIST OF MATERIALS NECESSARY FOR USE IN
CONNECTION WITH THESE OUTLINES

(Some of these may be omitted according to the discretion of the teacher. )

For Each Student

(a) Material which the student can bring to the classroom from home at different times.
Apple, knitting needle, string, pencil, ruler, plain paper, watch (where possible), small

bag or basket, steel knife or scratch point, window-glass fragment, drinking glass, piece of
candle, several small pieces of cheese cloth, several needles, coal fragment, baseball.

(b) Material which student may purchase.

Box of colored pencils (six different), cost 10 cents. Map of the United States 18x28
inches with contours, published by United States Geological Survey. Should be mounted
on cloth. Cost 10 cents.

(c) Material to be furnished by the school.

Small desk globe, simple compass dividers, several glass plates 4x4 inches approximately.
Copy of weather map, any date. Bar magnet. Several test tubes. Mineral and rock fragments,
unlabeled, following varieties : quartz crystal, orthoclase and plagioclase feldspar, hornblende,
halite, biotite and muscovite mica, calcite, gypsum, iron pyrites, dolomite, hematite, mag-
netite, granite, sandstone, fossiliferous limestone, schist, pumice, cellular lava, obsidian,
rhyolite, trachyte, syenite, gabbro, basalt, conglomerate, shale, gneiss, quartzite, slate, marble,
rock with lichen attached, rounded stream pebbles, residual soil from granite, residual clay
from limestone.

United States Geological Survey topographic sheets (should be mounted on cloth) as
follows : —

Montross, Maryland-Virginia. Lake Placid, New York.

Fargo, North Dakota-Minnesota. Saw Tooth, Idaho.

Donaldsonville, Louisiana. Chief Mountain, Montana.

Winterville, North Carolina. Spokane, Washington-Idaho.

Mt. Carrizo, Colorado. Granite Range, Nevada.

Syracuse, Kansas. Bright Angel, Arizona.

Kearney, Nebraska. Yosemite California Quadrangle.

Centerpoint, West Virginia. Map of Yosemite Valley, California.

Caldwell, Kansas. Shasta, California.

Whitewater, Wisconsin. Shasta Special, California.

Weedsport, New York. Cucamonga, California.

Niagara Falls and Vicinity, 1901, New York. San Francisco, California.

Cleveland and Vicinity, Ohio. Tamalpais, California.

St. Louis, Missouri. Boothbay, Maine.

Denver, Colorado. Barnegat, New Jersey.

Monterey, Virginia- West Virginia. Port Orford, Oregon.

Delaware Water Gap, Pennsylvania-New Jersey. Van Horn, Texas.

Mt. Mitchell, North Carolina-Tennessee. Crater Lake Special, Oregon.

Farmville, Virginia. Map of Home Region, if published.

xiii



For General Class Use

(a) Material of which the teacher may secure the rise without cost.

An egg, saucer, bottle, pebbles, shears, field soil from beneath sod, fruit jar, piece of
muslin, daily weather map.

(b) Material to be furnished by school. (Note. — Much of this material can probably be
borrowed from the physics and chemistry laboratories of the school.)

Several wall maps of different scale.

Wall map of the United States, showing railway lines.

Chart # 14 of the Mississippi River Commission.

Land model tank (see Suggestions to Teachers).

Several yardsticks.

Spray nozzle and rubber hose.

Several magnetic compasses.

Air pump.

Glass tube 35 inches long, closed at one end.

Bottle of mercury.

Funnel.

Mercury barometer.

Several thermometers.

Bottle of alcohol or ether.

Simple rain gauge.

Several sheets of wrapping paper.

Wooden rod.

Sheet of white cardboard.

Several hammers (geological, if possible).

Dilute hydrochloric acid.

Several glass stirring rods or dropping bottles.

Labeled hand specimens of the minerals and rocks listed on preceding page.

(c) Supplemental. Material which may be used if available.
Meteorological instruments.

Hand specimens of iron, gold, silver, copper, lead, and zinc ores.
Lantern slides for quizzes.

Note. — If teachers find difficulty in securing any of these materials, it is suggested that
they apply to the Geography Supply Bureau, Ithaca, New York.

Cross-section paper needed will be found at the end of the manual.



c



XIV



INDEX



Exercise w.
Exercise w.
Exercise w.
Exercise W.
Exercise #_
Exercise #
Exercise W.
Exercise W-
Exercise W-
Exercise #_
Exercise W~
Exercise #_
Exercise W.
Exercise #_
Exercise W.
Exercise w..
Exercise W.
Exercise W-
Exercise #..
Exercise ff .
Exercise w.
Exercise W.
Exercise $..
Exercise W.
Exercise W.



XV



(



e



INDEX



§



Exercise #_.
Exercise #_.
Exercise #_.
Exercise #..
Exercise #_.
Exercise #._
Exercise #..
Exercise #..
Exercise #_
Exercise F_.
Exercise #-
Exercise #_
Exercise #..

*

« Exercise #..

Exercise #..

Exercise #„.

Exercise #_.

Exercise #_

Exercise #..

Exercise ff.
I Exercise #..

Exercise #._

Exercise #..

Exercise #.
wi/' Exercise #_



xvn



(




THE EARTH AS A WHOLE



Materials.
Purpose.

A sphere
defined.



I.— SHAPE AND SIZE OF THE EARTH

For Each Student. — Desk globe. Apple. Knitting needle. String. Pencil. Ruler.

To gain an appreciation of the form of the earth and its dimensions.

Give a definition of a sphere in as few words as possible.



Name three objects that are spheres.



The earth
an oblate
spheroid. sphere ?



Is an apple a perfect sphere ? How do most apples differ from a true



What is the name given a spherical body that is flattened at the poles ?

Make a sketch to show how an oblate spheroid differs from a

true sphere.



%)



How much is the earth flattened at the poles?

Why are globes always made as true spheres, though the earth is an oblate spheroid ?

Meaning of What is meant by the diameter of a sphere?

diameter
and circum-
ference.

1



Thrust the knitting needle through the center of the apple, and with a ruler measure the
diameter of the apple. What is meant by circumference ?



With the string and ruler measure the circumference of the apple.
How many times greater than the diameter is the circumference ?



.. The circumference of a sphere is always that much greater than the

diameter. Since the diameter of the earth is a little over 7900 miles, how many miles is

the circumference ?



Meaning of Thrust the knitting needle through the center of the apple from the stem end ; then,

tanJu r restin £ one end of the needle on the desk, turn the needle so that the apple turns with it.
equa or. The need i e ig tne axig on w j 1 j c j 1 t ^ e app j e ro t a t es . What terms would you apply to the two

ends of the axis ? What does this experiment

illustrate with regard to the earth ?



What is the circumference of the earth midway between the poles called ?


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Online LibraryRalph S. (Ralph Stockman) TarrA laboratory manual for physical and commercial geography → online text (page 1 of 16)