LABORATORY AND FIELD EXERGISE5 IN PHYSICAL GEOGRAPHY GILBERT H. TRAFTON n i ii i m iiii iy i j i il Htl^aca. ^tto lath BOUGHT WITH THE INCOME OF THE SAGE ENDOWMENT FUND THE GIFT OF HENRY W. SAGE 1891 ENGINEERING LIBRARY Cornell University Library GB 23.T76 Laboratory and field exercises in physic 3 1924 005 017 425 Cornell University Library The original of tliis book is in tine Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924005017425 LABORATORY AND FIELD EXERCISES m PHYSI- CAL aEOORAPHY BY GILBERT H. TRAFTON, M.S. Lnstkuctok in Science in the High School, Passaic, N.J. GINN AND COMPANY BOSTON ■ NKW YOUK - CHICAGO • LONDON ATLANTA • DALLAS ■ COLUMBUS • SAN FRANCISCO A^u \ 'Soo Copyright, 1905 By GILBEET H. TBAFTON ALL EIGHTS KESEKVED A 518.11 VCie ia;ttienten>n jgteee GINN AND COMPANY • PRO- PRIETORS ■ BOSTON • U.S.A. PREFACE Physical Geography has at last come to take its place among the other sciences as a subject which requires labora- tory and field work for its highest development. The reasons for the introduction of laboratory methods in this subject are the same as those which demand its use in the other sciences, namely, the training which the pupil receives in the laboratory and the additional light thrown upon the subjects discussed in the class room. As Physical Geog- raphy is so generally assigned a place in the first year of the high-school course, it is of special importance that this first science should be so taught as to inculcate scientific methods of study. But while the need of laboratory work is universally recognized by the leading educators, this adjunct has not yet found its way into the methods of the majority of our secondary schools. The causes we need not go far to seek. This newer feature of laboratory work in Physical Geog- raphy has been introduced in such comparatively recent years that there has not yet been sufiicient time for schools and teachers to adapt themselves to the changed conditions. This is simply a repetition of what has happened in the development of the other sciences. Another reason for the delay ia introducing laboratory methods into many of our schools has been that, until very recently, there has been published no laboratory guide which could be placed in the hands of the pupils, such as had been prepared in the other sciences. Within the last iv PREFACE decade there, have appeared enough suggestions to enable one to formulate a satisfactory laboratory course, but this material is so scattered that it requires some little time to collect it and a still longer time to put it into such shape that it may be used to advantage in the laboratory. These exercises are published with the thought that this difficulty may be partly overcome, and that those teachers who do not have the time to develop this subject from the very start may be saved much time and labor and be enabled to introduce laboratory methods into their courses earlier in their experience than they niight otherwise do. And even for those who have already worked out their own labora- tory exercises, it is hoped that these may prove helpful in their suggestions and in providing directions for the guidance of the pupil. I take pleasure in making special acknowledgment of the kindness of Professor W. M. Davis. He has very kindly read over my manuscript, making valuable sugges- tions, and has allowed me to use plates and figures from his text-books. Some of the exercises included here were first suggested to me by his writings, as Exercises I and II; and the other exercises in his Elementary Physical Q-eography have also been suggestive in planning my outlines. Thanks are due also to Professor R. E. Dodge for suggestions on Chapter V. GILBERT H. TRAFTON PAaSAic, N.J. CONTENTS CHAPTER I. THE WORLD AS A GLOBE EXERCISE PAGE I. To find a North and South Line 1 II. To find the Latitude . . 2 III. To demonstrate the Rota- tion of the Earth and to find the Latitude . . 3 IV. Relation of the Earth to the Sun 6 V. The Seasons 6 VI. Relative Positions of Sun, Earth, and Moon at the Different Phases of the Moon 8 VII. Distances on the Earth drawn to Scale ... 9 CHAPTER n. THE LAND VIII. Study of a Topographic Map of your Locality . 11 IX. To make a Cross Section of the Contour Map used in the Preceding Exercise 14 X. Study of a Haohure Map 15 XI. To reproduce in Haohures a Part of the Contour Map of the Wicomico Region, Maryland . . 16 Rivers XII. Flood Plains 18 XIII. River Terraces ... 18 XIV. Lengthvfise and Crosswise Valleys 10 XV. Young Rivers . . 20 XVI. Mature Rivers . . . 20 EXERCISE PAGE XVII. Old Rivers .... 21 XVIII. Longitudinal Profiles of Rivers 22 XIX. A Study of the Missis- sippi River .... 24 Glacial Eormations XX. Glacial Moraines . . 25 XXI. Drumlins 26 . 27 . 28 . 29 . 30 Plains XXII. Coastal Plains . . xxiii. Lake Plains . . . XXIV, Glacial Plains . . XXV. Worn-Down Plains Plateaus XXVI. Young Plateaus ... 30 XXVII. Dissected Plateaus . . 31 xxvm. Old Plateaus ... 31 Mountains XXIX. Dissected Block Moun- tains 32 XXX. Domed Mountains . 33 XXXI. Massive Mountains . . 33 XXXII. Worn-Down Mountains which have again been uplifted ... 34 XXXIII. Appalachian Ridges . 36 Volcanoes XXXIV. Young Volcanic Moun- tains 37 XXXV. Maturely Dissected Volcanic Mountains 38 XXXVI. Old Volcanic Moun- tains. Volcanic Necks 38 VI CONTENTS EXERCISE PAGE XXXVII. Lava Plateaus . . ' . 39 xxxvm. A Crater containing a Lake 39 XXXIX. Identification of Land Forms ... 40 XL. Study of Minerals 41 xLi. Study of Rocks . 42 Field Work XLii. Weatliering .... 42 xLiii. Stream Action ... 43 XLiv. Drift 46 CHAPTER III. THE ATMOSPHERE XLV. Weatlier Observations 49 xLvi. To find tlie Height of a Hill by Means of a Barometer ... 52 xLVii. To find the Dew Point 53 XLViii. Annual Distribution of Rainfall ... 53 XLix. The Effects of Lands and Oceans on Tem- perature . . . .55 ij. The Heat Equator and Cold Pole ... 56 LI. A Comparison of Tem- peratures for Jan- uary and July at 40° North and South Latitude .... 58 Lii. Effects of Seasons on Winds 59 Liii. Study of a Weather Map 60 Liv. Comparison of the Con- ditions that exist in Cyclones and Anti- cyclones ... 61 Lv. To find the Average Rate and Direction of Motion of Cy- clones ... 63 EXERCISE PAGE Lvi. To predict the Weather for Twenty-Four Hours ahead of the Date of the Map fur- nished you . . . .64 LVii. To construct a Weather Map 68 CHAPTER IV. THE OCEAN Lviii. To make a Profile of the Bottom of the Atlan- tic Ocean and the Ad- joining Land . 71 Lix. Ocean Currents ... 72 Lx. Shore Lines . . .73 CHAPTER V. DISTRIBUTION OF LIFE IN UNITED STATES AND NORTH AMERICA LXi. Distribution of Cereals 75 LXii. Distribution of Sugar Cane and Sugar Beet 77 Lxiii. Distribution of Fruits . 78 Lxiv. Distribution of Cotton . 79 Lxv. Distribution of Forests . 80 Lxvi. Distribution of the Great Areas of Vegetation . 81 Lxvii. Distribution of Animals 83 Lxviii. Density of Population . 85 APPENDIXES A. Suggestions to Teachers 87 ' B. Material needed for the Work outlined . . 92 C. List of Books and Mag- azines giving Sug- gestions concerning Laboratory and Field Work .... 95 D. Lists of Laboratory Exercises . . 98 LABORATOEY AND FIELD EXERCISES IN PHYSICAL GEOGRAPHY CHAPTER I THE WORLD AS A GLOBE EXERCISE I To FIND A NOKTH AND SoUTH LiNE Place 1 a table before a window through which the sun shines at noon. Place on the table a sheet of paper and put weights on it to keep it from moving. Stand on the paper a small chalk box, or other square-cornered box, on end. At 11 : 15 mark the position of the shadow of a cor- ner of the box. Do the same at 11 : 30 and 11 : 45, then for every five minutes till 12 : 15, and finally at 12 : 30 and 12:45. Draw a line connecting these points. Mark the position on the paper of the corner just below the one the position of whose shadow has been taken. Draw the short- est line possible from the lower corner of the box to this line. To do this, use as a center the dot marking the posi- tion of the comer of the box, and with a pencil and string draw an arc of a circumference which shall touch the line 1 To THE Pupil. Write in a notebools all that you do under each exercise. Write answers to the questions asked and make a record of all other observa- tions made. 1 2 LABORATORY AND FIELD EXERCISES previously drawn at only one point. Connect this point with the center of the circle. This line will be a north and south line. Why? Before moving the paper find some fixed objects that have the same direction as this line, such as some edge of a building or the line connect- ing two posts or trees. Fold the paper and paste in your notebook. EXERCISE n (.see Appendix A) To FIND THE Latitude (^Approximately) Apparatus. Take a piece of lath about a foot long and screw it 1 inch from the end to the side of a sharpened post, which should be about 8 inches long, with the upper part square and the lower part round. Saw off the end Fig. 1 of the lath at an acute angle, as shown in the figure. Provide five sharpened stakes about | inch square, two of which should be a foot long, two 1^ feet, and one 2 feet. Drive the stake, with pointer attached, about two thirds of the way into the ground. In the early morning turn the pointer toward the sun. The correct position may be found by holding a piece of paper behind the pointer and turning the lath till its shadow is of the same size as the end of the lath itself. Drive a stake into the ground so that the tip of the pointer just touches the top of the stake at the inner corner. In the same way mark the position of the end of the pointer at each of four other observations taken, one during the middle of the forenoon, one at about THE WORLD AS A GLOBE 3 noon, one during the middle of the afternoon, and one a little while before sunset. Procure a piece of board 2^ feet long by 1^ feet wide, or two narrower pieces may be fastened together by means of a cleat. Placing one edge of this on the ground, allow it to rest on the tops of the stakes so that each stake touches the board. This marks out a plane parallel to that followed by the sun during the day. The angle which this plane makes with a perpendicular is the latitude. Why? To find this angle, procure a protractor and suspend from its center a pendulum. Go 10 or 15 feet to one side and, sighting at. the board with the protractor so that its edge shall be in line with the board, read the angle which the board makes with the pendulum. To determine the amount of error, compare your result with the latitude as found on a map of your state. EXERCISE in To DEMONSTRATE THE ROTATION OF THE EaETH AND TO FIND THE LATITUDE The requisites for this experiment are a long pendulum, consisting of an iron ball of several pounds weight sus- pended by as small a wire as will hold it, and a high support for the pendulum. This last condition can be found in the open space in the stairway of the school building, where the height of several stories can be utilized. Screw a hook into the ceiling just over the center of the open area, in such a position that it will be in a plane at right angles to that in which the pendulum is to vibrate, thus reducing friction. Pass the wire over the hook and fasten it, allowing the ball to swing just free from the floor. Draw a chalk line on the floor in the plane in which 4 LABORATORY AND FIELD EXERCISES , the pendulum is to vibrate, allowing this line to pass through the point just beneath the center of the ball. Make a loop of a piece of string, and passing it around the greatest diameter of the ball, pull it back and fasten it to a support placed oyer the chalk line. See that no doors or windows are open to cause a draft. Burn off the string with a match. Record the time. Watch till the bob nearly stops swinging. What results do you observe ? What is the explanation ? In which direction is the bob deflected ? If the pendulum were set swinging at either pole, how would the results differ? How at the equator? How at other points between ? As the time required for the meridian to rotate depends on the distance of the station from the equator, this experi- ment furnishes a means of finding the latitude. When the bob has nearly stopped, find the direction in which it swings. Take two pieces of string about a yard long and attach to each a small weight. At either side of the extreme of the vibration of the swinging bob suspend one of these small pendulums and arrange them so that they shall be in the same plane as that in which the bob swings. Take the time, and mark a pdint on the floor just beneath each of the small bobs, connecting these points by a chalk line. Measure the angle which this line makes with the line first drawn. You now have the angle of deflection and the time taken for it. Compute the angle of deflection for an hour. Divide 360° by this angle and this will give the number of hours required for a complete rotation of the meridian. Divide 24, the number of hours in a day, by the number previously obtained, and the quotient will be the sine of the latitudeof your locality. From the table ascertain the angle which corresponds, to this sine. This is your approximate latitude. Compare with the result of THE WORLD AS A GLOBE 5 the pievious experiment and with the latitude as found on a map of your locality.^ Table of Sines Sine Angle Sine Angle Sine Angle Sine Angle .500 30 .574 35 .643 40 .707 45 .515 31 .588 36 .656 41 .719 46 .530 32 .602 37 .669 42 .731 47 .545 33 .616 38 .682 43 .743 48 .559 34 .629 39 .695 44 .755 49 EXERCISE IV Relation of the Earth to the Sun Procure a piece of paper 20 inches square. Through the center draw a line parallel to the edge. Let each inch represent a distance of 10,000,000 miles. On each side of the middle of the line place a pin, so that they shall be 3_ inch apart. How many miles does this represent? With a piece of thread that will not stretch make a loop 19 inches around. Put one end of this loop around the pins, and with a pencil at the other end draw a curve around the pins, keeping the string taut. This curve is an ellipse and represents the form of the earth's orbit around the sun. Around one of the pins draw a circle to scale to represent the sun, whose diameter may be taken as 1 For more detailed suggestions see Goode in the Journal of School Geography, October, 1899. 6 LABORATORY AND FIELD EXERCISES 1,000,000 miles, although really about \ smaller than this. What will the diameter of this circle be ? What would be the size of a circle to represent the earth, whose diameter is about 8000 miles? The points where the ellipse cuts the straight line represent the extremes of the distances of the earth from the sun. Label the point nearest the sun " peri- helion," and the other point " aphelion." From the length of the lines and the scale used determine each distance. Through the focus at which the sun is situated draw a perpendicular to the line first drawn in this exercise till it intersects the orbit on either side. About 1^ inches from each of these points, measured ' clockwise on the circumference, make a dot. These dots represent approxi- mately the position of the equinoxes. Place the paper with perihelion at the right and mark the point on the upper side " vernal equinox," and the other point " autumnal equinox." Indicate the direction of the earth's motion by arrows. exercise v The Seasons 1. On the point marked "perihelion" in the previous experiment place a small globe or a wooden ball sup- ported on a wire. Move it clockwise on the circumference about 1^ inches. Tip the axis of the globe away from the sun till it forms an angle of 231° (about ^ of a right angle) with a perpendicular to the plane of the orbit. This rep- resents the position of the earth on December 21. 2. At the focus where the sun is located set up a pin or piece of wire of such a length that its end is opposite the center of the globe. Allow this end to represent the position of the sun. THE WORLD AS A GLOBE 7 3. Take a piece of wire a little longer than the circum- ference of the globe and bend it around the globe in a great circle in a plane perpendicular to a line extending to the point representing the sun. This wire marks the limits of that half of the globe which receives sunshine at any given moment. Keeping this unchanged, turn the globe on its axis to show the succession of day and night and answer the following questions. (a) Is there any region that receives no sunlight during the day ? How many degrees from the pole does it extend ? What name is given to this zone ? What conditions pre- vail at the other pole ? (b) How many degrees south of the equator is the sun seen directly overhead at this time ? What name is given to the zone within these limits on either side of the equator ? What are the zones between this one and those around the poles called? (c) How do night and day in each zone compare in length ? (d) Which hemisphere receives the more sunshine, the northern or southern? (e) How does the inclination of the sun's rays vary as you pass from pole to pole ? 4. Place the globe on a point 1^ inches from the aphelion, toward the vernal equinox, keeping the axis parallel to its first position. This represents the position of the earth on June 21 . Answer the same questions as in the preceding case. 5. Place the globe at the equinoxes and at each one an- swer questions (c), (d), (e), and the first part of (a). 6. What zones always have sunlight at some time dur- ing each twenty -four hours? 7. As a result of your observations state what two fac- tors cause the change of seasons. In what way do these 8 LABORATORY AND FIELD EXERCISES factors act so as to cause the earth to receive more heat in the summer than in the winter? When is the earth nearest the sun, in winter or summer? What effect does this have on the range of temperature during the seasons ? 8. Place the globe so that its axis is perpendicular to the plane of its orbit, and determine what the effect would be on the various zones at the different seasons of the year. Place the globe so that its axis is parallel to the plane of its orbit and determine the effects. 9. Make these same observations at home in the even- ing, using a lamp to represent the sun. 10. What part of your exercise illustrates the cause of day and night? What is the cause? EXERCISE VI Relative Position of Sun, Earth, and Moon at the Different Phases of the Moon 1. Allowing a line 1 inch long to represent 8000 miles, what would be the diameters of circles representing the moon, earth, and sun, whose approximate diameters are respectively 2000, 8000, and 900,000 miles? On the same scale, how many feet from the circle representing the earth would those circles representing the moon and sun be placed, the distances being respectively about 250,000 and 93,000,000 miles? 2. In the following exercise no attempt is made to draw the various circles to the same scale. At the right-hand side of your notebook draw a circle 2 inches in diameter to represent the moon's orbit, which is really an ellipse. On the left-hand side of the page just opposite draw a circle ^ inch in diameter to represent the position but not the relative size and distance of the sun. THE AVORLD AS A GLOBE 9 Make a dot at the center of the first circle to represent the position but not the size of the earth. Draw four cir- cles, each of ^ inch diameter, using as centers the point nearest the sun, the point farthest away from the sun, and the two points halfway between these positions — points on the circumference of the right-hand circle — to repre- sent different positions of the moon. Fill in with lead pencil that half of each circle which is away from the sun and so receives no light, leaving the other portion white to represent the illuminated portion. 3. When the moon is nearest the sun, how much of the illuminated portion can be seen from the earth? What phase of the moon is this called ? When the moon is farthest from the sun, how much of the illuminated por- tion do we see ? What phase of the moon is this ? What portions do we see when the moon is halfway between these points ? What phases are these ? 4. At what phases of the moon are the sun, earth, and moon nearly in a straight line ? EXERCISE VII Distances on the Earth deawn to Scale 1. What is the circumference of the earth expressed in the nearest thousands of miles? Allowing a line 1 inch long to represent 5000 miles, draw a straight line to rep- resent the length of the circumference of the earth. 2. Just under it draw another to represent the diameter of the earth. 3. On a blank weather map of the United States find the distance in miles in a straight line from New York City to the following cities, using the scale of miles given on the map : San Francisco, Chicago, Washington, Boston. 10 LABORATORY AND FIELD EXERCISES Using the same scale as in 1 and 2, draw lines to represent these distances. 4. Label each line, showing the distance it represents. What proportion of the diameter of the earth is the dis- tance from New York to San Francisco ? What distance would one travel if he were to start from New York and go eastward till he reached San Francisco ? 5. Using the same scale as before, draw a straight line to represent the distance around that part of the United States represented on the map. CHAPTER II THE LAND EXERCISE VIII {see-Appendix A) Study of a Topographic Map of youb Locality 1. (a) Contour lines. These are the brown lines found on all parts' of the map. Before studying these, make the following preliminary study. Make a small model of a mountainous country, which, in addition to valleys, spurs, steep slopes, and peaks, should contain also a level area. This may be made by first nailing together blocks of wood cut out so as to give the general outline desired. This may then be covered with putty by means of which the finer details of relief may be molded. Pieces of iron or lead should be attached to the base of the model, sufficiently heavy to keep it from floating when submerged in water. Place the model in a water-tight receptacle a little higher than itself. A box with glass sides, similar to those used for aquaria, is most satisfactory, but in place of this a tin box made by the tinsmith may be used. In place of the apparatus just described, the following much simpler equipment may be used. Secure an ordi- nary battery jar and a stone small enough to go inside and of such shape as to represent some land form. A little searching among a pile of stones will usually enable one to find some which are fair types of hills, ridges, and val- leys. While the finer details cannot be shown as clearly as with a specially prepared model, yet the meaning of 11 12 LABORATORY AND FIELD EXERCISES contour lines can be brought out quite as well with the stones as with the special model. If the stones are used, a smaller contour interval than that suggested in (b) will need to be taken. (b) Pour into the box or jar enough water to cover the base of the model. Having provided a sheet of paper of the same size as the base, draw a line near the edge to correspond with the water line on the model. Add suffi- cient water to raise the level ^ inch. Draw another line just inside the first to represent the new water line. Pro- ceed in this way to add water ^ inch at a time till only a small peak of the model is left uncovered. After each addition of water draw a line on your paper to correspond with the coast line of the model. Take special care to see that the distance of the line from the edge of the paper shall be the same as the horizontal distance of the water line from the edge of the model. (c) You have now made a contour map of the model, each line that you have drawn representing a contour line. The contour interval is ^ inch. How much is the contour interval on the topographic map of your locality? Explain what this means. (d) Find on the map you have drawn the following arrange- ments of contours, and by comparison with the correspond- ing parts of the model explain what each of the following signifies: (1) close together, (2) far apart, (3) in circular rings, (4) bending in towards the center of the model, (5) bend- ing out away from the center of the model. On the topo- graphic map find each of these arrangements of contours. (e) Mark the first line drawn on your map " sea level." Mark the elevation above this line of every fourth contour and also. of the highest point. On the topographic map find the elevation of the highest spot and the lowest spot. THE LAND 13 (/) From a study of the model and the map that you constructed, determine the relation between the direction of contours and the direction of the slope. {g) What is the meaning of the heavy brown contour lines found on the topographic map? (A) How do the elevations of contours adjacent to each side of a stream compare ? (i) Find the relief in the vicinity of the largest stream, that is, the difference in elevation between the stream bed and the divide. U) What three general heads will include all the fea- tures shown by the contours ? 2. (a) By what survey and under whose direction was your map made ? (h) What is the name of your sheet ? (c) What is the scale — how many miles to an inch? 3. Draw in your notebook an outline map of the state in which your map is situated, and mark on it the location of your map by a small rectangle of the correct propor- tionate size- 4. Find the following and explain what they signify: (a) blue lines, (5) heavy black lines with cross lines, (c) fine black lines which are in pairs and parallel, {d) small black squares. 5. Name a few of the principal rivers, lakes, and towns found on your map. 6. Find the fall per mile of the largest stream. To do this, find the point where the stream enters the map and take the elevation at the first point where the stream is crossed by a contour. In a similar way find the elevation where the stream leaves the map. From the elevations of these two points and the distance between them as the stream runs, find the fall per mile. Compare the total fall of the first half of the distance with that of the second half. 14 LABORATORY ANI> PI ELD EXERCISES 7. Determine the best bicycle road between two selected places as far apart as the map will permit, and find the distance between them. Distance and grade must both be taken into consideration. Describe the country along the route chosen. 8. Imagine yourself to be standing on the summit of some hill, and determine how far you can see north, east, south, and west. Write a description of the country to be seen from this point. EXERCISE IX (sec Appendix A) To MAKE A Cross Section of the Contour Map used IN THE Preceding Exercise In your notebook, near the bottom of the page, make a line of the same length as the one drawn by the instructor on the map, and make dots to correspond in position with the cross lines on the map. In thus copying the length of the line you are using the same horizontal scale as is found on the map. What is it? Number the dots to correspond with the cross lines. Find the elevation of cross line No. 1. Write the number of feet under the figure 1 in your note- book. In the same way write the height for each of the other cross lines. For the vertical scale take Jg inch for every 100 feet. Measure up from your line distances to represent the elevation under each dot. For instance, if the elevation of point No. 1 is 700 feet, measure up from the line -^-^ inch and make a dot at this place. Proceed in the same way with the other elevations. Draw a smooth line connecting these points. Using the same base line as in the previous exercise, make another cross section with the same horizontal scale as above, but with the vertical scale 1 inch to 5000 feet. THE LAND 15 This will make tlie horizontal and vertical scales about the same. This is the true profile. How much is the ver- tical exaggeration in the first section? In both of these sections mark in blue bodies of water crossed by the line. Label the profiles and write near them both the horizontal and vertical scales. Do the same with every profile made. exercise x Stupy of a Haohuke Map Fig. 2. Reprksextaiion of Kelief r,v Haciiuues 1. Find on the map each of the following features and explain what it signifies : (a) a white oval or circular spot with lines radiating from it in every direction, (b) long and 16 LABORATORY AND FIELD EXERCISES fine lines, (c) short and heavy lines, {d) black areas without distinct lines, ie) places where rows of lines come together, forming a letter V. 2. To make a profile of a hachure map, draw a line connecting the summits of two hills and extended so as to be about 2 inches long. In your notebook draw a line of the same length. On this make dots to indicate the location of hills and valleys. About an inch above this line make a profile, using the dots as guides in placing the hills and valleys. Be careful to have the profile slope gently where the lines are long and fine, more steeply where the lines are short and heavy, and very steeply where there are black areas without distract lines. EXERCISE XI (see Appendix A) To EEPRODUCB IN Hachuebs A Pakt of the Contour Map of the Wicomico Eegion, Maryland 1. Reproduce as much of the lower right-hand comer of the Wicomico sheet, Maryland, as is included between the edges of the map, 38° 20' latitude and 76° 50' longitude. 2. Draw a rectangle in your notebook of the same size as this one on the map. Draw lines to represent the streams and the eastern shore line of the Wicomico River. 3. Review your observations in the eighth exercise under 1 (/). Wherever there is a level area leave this without shading. In the northern part of the rectangle is a flat- topped hill bounded by the 140-foot contour line. Copy this line lightly in your notebook. Beginning with this, draw the hachures for the rest of the area, showing the direction of the slopes by the direction of the hachures, and the amount of slope by the length and shading of the hachures, none of which should cross the streams, THE LAND 17 making long fine hachures for gentle slopes and short heavy ones for steep slopes. Do not make any of the lines longer than | inch, and whenever the slope changes, show the change by a difference in the hachures. When all the area is finished, carefully erase the line drawn to represent the 140-foot contour. In the remaining map studies the cross sections are to be constructed in the same manner as the one already made in Exercise IX, only no line is to be drawn on the maps. Instead, lay a piece of paper on the map so that its edge connects the points between which the profile is to be drawn. Make dots on the paper opposite the points whose elevations are to be taken, and under each dot put the elevation of that point. Now lay the paper on your notebook, and draw a line equal in length to the distance marked to show the limits of the profile. On this line mark the dots and elevations to correspond with those on the paper. Then proceed as in the previous case to con- struct the cross section. Whenever reference to lines on the maps is made in connection with these profiles, it will be understood that these indicate direction only and that no line is to be drawn. In each case mark the position of the streams by blue lines of the correct proportionate length. The purpose of the observations called for in the follow- ing map studies is to bring out the topographic features. At the close of each exercise the pupil should try to picture in his mind the appearance of the land the map of which he has been studying. 18 LABORATORY AND FIELD EXERCISES EIVEES EXERCISE Xn (see Appendix A) Flood Plains Bonaldsonville Sheet, La. 1. Note scale and contour interval. This is the first thing to be done in the study of each of the following maps. 2. Where is the highest part of the plain? On what, then, is the river flowing ? 3. What is the nature of most of the area ? 4. How high above sea level is the lowest part of the region? And yet it is 150 miles from the sea as the river flows. 5. Does Bayou Conway flow toward or away from the river ? 6. What determines the direction of the main roads ? Where are the settlements located? 7. Make a profile along a line crossing the word " river " and extending on each side to the marsh. Horizontal scale as on the map, vertical scale 1 inch to 100 feet. Take the elevations at the ends of the line and at the contours nearest each side of the river. EXERCISE Xin EivEE Terraces Springfield Sheet, Mass. 1. Make a profile along the line of 42° 10' latitude between longitude 70° 36' and 70° 40' (horizontal scale as on map, vertical scale 1 inch to 200 feet). Take the THE LAND 19 elevations at the ends of the line, at each side of the river, at the heavy contours on the west side, and at the 200-foot and 80-foot contours on the east side. 2. As you pass from the east end of the line to the 200-foot contour, what is the nature of the land ? What is it between the railroad and river? What separates these two stretches ? How has the level area just east of the river been formed? Does its similarity to the area at the top of the bank suggest how the upper area may have been formed? In what ways must the conditions have differed from those found now? EXERCISE xrv Lengthwise and Crosswise Valleys Harper's Ferry Sheet, Va., W. Va., Md. 1. Find the lengthwise valley west of the Blue Ridge and the crosswise valley cutting across the Ridge. 2. Describe the first valley. Describe the second valley where it cuts the Blue Ridge. 3. What is the local base level of the Shenandoah River ? 4. If, on account of a difference in the hardness of the rock, the Shenandoah should do its vertical erosion more quickly than the Potomac, in what way would the first river use its extra time and energy ? Do you see any evi- dence on the map that bears out your answer ? 5. Make a profile of the crosswise valley from Maryland Heights to Londoun Heights, and one of the lengthwise valley from Londoun Heights to Leetown (horizontal scale as on map, vertical scale 1 inch to 1000 feet). In each case take the elevations at the ends of the line, at each side of the river, and at the heavy contour lines. 20 LABORATORY AND FIELD EXERCISES exercise xv Young Eivees Echo Cliffs Sheet, Ariz, 1. Make a cross section from the letter y to the letter v in the word " Yavapai" (horizontal scale 1 inch to 2 miles, vertical scale 1 inch to 1000 feet). Take the elevations at the ends of the line and at the heavy contours. 2. Find {a) the fall per mile of the Colorado River^ (b) the width of the canyon at the top ; (c) describe the slope of the valley sides. 3. (a) How does the width of the valley bottom com- pare with the width of the stream? (h) Are there any flood plains? 4. What do you find about the distinctness of the divide between Navajo Creek and the Little Colorado River? Is its location ill defined or sharply defined ? exercise xvi Mature Rivers Charleston Sheet, W. Va. 1. Make a profile from Rocky Fork to the western end of Grapevine Knob (horizontal scale as on the map, verti- cal scale 1 inch to 1000 feet). Take the elevations at each end of the line, at the carriage roads, and at the highest point between two adjacent roads. 2. In studying the features of mature and old rivers keep in mind the conditions found on the previous map or maps. 3. (a) Describe the slopes found here. (6) Find the fall of the Kanawha River, (c) How does the slope of the THE LAND 21 smallei: streams compare with this? (d) Does the Kana- wha have a flood plain? 4. How do the slope of the banks and the width of the valley bottom compare with these features in the Colorado, as found on the preceding sheet ? 5. How many lakes do you find? 6. Find the divide between the Coal and Kanawha rivers. Can its position and limits be distinctly located ? How wide is it? 7. (a) Are the tributaries few or numerous ? (b) Is there opportunity for them to increase their length by cutting back at their headwaters ? How does this compare with the tributaries of the Colorado ? (c) Do you find any area that is not well drained ? EXERCISE xvn Old Eiveks Caldwell Sheet, Kan. 1. Make a cross section along the carriage road running north and south through Milan, extending five squares on either side (horizontal scale as on map, vertical scale 1 inch to 1000 feet). Take the elevations at the contours on each side of the streams and at the contours nearest the inter- sections of the roads. 2. (a) Find the fall of the Chibaskia River. (J) What do you note about the course of the river? 3. Describe the width, appearance, and distinctness of the divide between this river and Slate Creek. 4. How much is the difference in elevation between the lowest and highest points ? 5. Describe the slopes found here. 22 LABORATORY AXD FIELD EXERCISES 6. In what kind of lines do the carriage roads extend? What does this indicate ? 7. What do you note about the number and location of villages? Does the region seem to be favorable for settlement ? 8. From a study of your notes and profiles of these three maps make a comparison of the characteristics of youth, maturity, and old age in the tabular form given below, which should be copied in your notebook. Age of River slope of Valley Sides A'flocity of Jiarger Streams Character of Divides Width of Valleys Youth Maturity Old Age EXERCISE XVIII Longitudinal Profiles of Rivers a. Of the Yellowstone River 1. Four inches from the top of your notebook draw a straight line 6 inches long. This is to represent the level of the mouth of the river, from which the heights of the river are to be measured. 2. Beginning at the left of the line, measure off from the end each of the distances from the mouth given in the second column, on the scale of 1 inch to 100 mile.s. Make a dot on the line for each distance and number them to correspond with the numbers in the first column. THE LAND 23 Under each of these numbers put the corresponding height above the mouth level. 3. Measure up from the line distances to correspond with the heights above the mouth on the scale of 1 inch to 2000 feet. Make a dot in each case at the proper dis- tance. Connect these dots by a smooth line slightly concave upward. b. Of the Ohio River 1. One inch below the base line previously drawn, con- struct another line 11 inches long. Using the table, pro- ceed as in the previous case to construct a profile of the Ohio. 2. (a) In what stage of development is each of these rivers ? {h) What differences in form do you note between these two profiles ? (c) In what part of the Yellowstone do you find the steepest slope? In what part the gentlest slope? Distance from Mouth Height above Level of Mouth 1 100 miles 245 feet 2 215 " 610 " 3 331 " 1224 " 4 400 " 1992 " 5 486 " 3145 " 6 533 " 4145 " 7 552 " 5445 " 8 569 " 5886 " Distance from Moutli Height above Level of Mouth 1 123 miles 27 feet 2 378 " 120 " 3 744 " 270 " 4 963 " 428 " 5 1048 " 588 " 24 LABORATORY AND FIELD EXERCISES EXERCISE XIX A Study of the Mississippi Eivek Map of the Alluvial Valley of the Mississippi River 1. The flood plain is tinted blue and the land above flood levels white (scale 5 miles to an inch). The figures near the river indicate distances from Cairo, 111., as the river runs. 2. What is the form of the lower end of the delta? How many distributaries or passes are there ? 3. Does Bayou La Fourche flow toward or away from the river ? Do you find other distributaries ? 4. What is the first distributary as you follow the river south from Vicksburg? If the point where this leaves the river be taken as the head of the delta, how far out has it been built? From measurements on the map, esti- mate approximately the area of the delta. What cities have been built on this delta ? 5. What is the position of the 'river with reference to its flood plain ? 6. What is the average width of the flood plain above the head of the delta ? 7. (a) What do you note about the location of the lakes with reference to the flood plain and the land on either side ? (J) What is the shape of the lakes near the river? (c) Do you find any part of the river that will be soon left as a cut-off or lake as the work of the river progresses ? Make a drawing in your notebook to illustrate this feature. 8. What is characteristic of the course of the river through the whole length shown on these maps ? How far is it in a straight line from the point where the river enters the map at latitude 34° 20' to where it leaves it at latitude 33° 10'? How far does the river flow in going this distance? THE LAND 25 GLACIAL FOEMATIONS exercise xx Glacial Mokaines Eagle Sheet, Wis. 1. What is characteristic of the courses of the streams? 2. What else do you notice concerning the water fea- tures shown here ? 3. What is the appearance of the land between the streams ? 4. Are the contours sinuous or even? What is thus shown concerning the regularity of the surface ? 5. How does a section across Fox River above Lake Mukwonago compare with one just below the lake? 6. How does the relief at different points on the map compare? For example, compare the relief just northeast of Eagleville with that just south. 7. (a) Do you find any ponds without outlet? (6) In the stream north of Eagleville how does the slope of the upper half compare with that of the lower half ? In our study of the Yellowstone and Ohio rivers what kind of longitudinal profile did we find that a river tends to make ? (c) What do your observations under [a) and (h) show con- cerning the age of the streams and land features found here? Give reasons for your answer. 8. In the Third Annual Report of the United States Geo- logical Survey examine plates facing pages 318 and 370. 26 LABORATORY AND FIELD EXERCISES EXERCISE XXI Dkumlins Sun Prairie Sheet, Wis. 1. What is the shape of the hills found here ? 2. What is their average height above the surrounding country ? 3. What do you notice about the direction of their longer axes ? Can you explain ? 4. What is the nature of the land between these hills ? 5. What do you observe concerning the number of streams and their courses? 6. What is the relation of the streams to the drumlins — do they cut through or How around them ? What is thus shown concerning the relative age of the hills and streams ? Were the courses of the streams carved after or before the hills were formed? 7. Are the sides of the drumlins smooth or are they dissected by streams ? What do you infer concerning the time that these hills have been exposed to erosion ? 8. See Fig. 103 in Gilbert and Brigham's Introduction to Physical Geography. 9. Does the parallelism of the longer axes of these drumlins, extending in the same general direction as that in which the glacier moved, suggest any explanation regarding the way in which these drumlins may have been formed ? 10. What other maps have you studied that show the influence of the glacial period on man ? THE LAND 27 PLAINS EXERCISE XXn Coastal Plains Grlassboro Sheet, N. J. 1. (a) What do the tufts of blue lines beside the streams signify ? ' (6) Find the fall of the Maurice River. 2. What is the appearance of the interstream areas? What is their average height? 3. {a) Are the valleys shallow or deep? (h) Do the branches of the principal streams cut back so that their sources are near together and all the area is well diained, or are there level areas on which no streams are found ? 4. What is the average relief along the Maurice River ? 5. What is the difference in elevation between the highest point in the northern part and the highest point in the southern part of the map ? About how many miles apart are they ? 6. (a) What do you note about the location of the roads and railroads with reference to the valleys and interstream areas ? (b) In what kind of lines do they extend ? Why ? Are the roads around your home similar ? Why ? 7. What do you note concei'ning the number, size, and location of the villages? Does the map suggest a reason for their location ? 8. Make a profile along a line just above the village of Clayton, beginning at the letter Y and extending east 5 inches (horizontal scale as on the map, vertical scale 1 inch to 200 feet). Take the elevations at the ends of the line, at the contours on either side of the streams, at the letter 0, and at the highest point between the two streams. 28 LABORATORY AND FIELD EXERCISES 9. Summarize briefly in a sentence the features of the land represented on this map as regards (a) elevation, (h) slope, (c) relief. EXERCISE XXra Lake Plains a. Fargo Sheet, JV. Dak. 1. What is the elevation of the region expressed in nearest hundreds of feet ? 2. What is the average distance between the contour lines ? What is thus shown concerning this region ? 3. Where are the roads and buildings located ? Judging from their number, does the region seem to be weU adapted for settlement? 4. What do you observe concerning the number and courses of the streams? Describe the valleys as regards width and depth. 5. Make a profile along the line of 46° 50' latitude, be- ginning with the contour at the east bank of the Sheyenne River and extending to the third contour east of the Red River (horizontal scale as on the map, vertical scale 1 inch to 200 feet). Take the elevation of each contour crossed. 6. This region was once the bed of a huge lake of glacial times, Lake Agassiz, of which Lake Winnipeg is a remnant. On account of the fertility of the soil and the level surface, this country is one of the best wheat regions in the world. 5. Toele Valley Sheet, Utah 1. The area represented on this map is a part of the Great Basin region. In what direction do the mountains extend? What is the appearance of the areas between these mountains ? THE LAND 29 2. What becomes of most of the streams that flow down from the mountains ? Can you suggest an explanation ? 3. The areas between the ridges were once the bottom of a great lake, Lake Bonneville, of which Great Salt Lake is a shrunken remnant. 4. For illustration of the features of this old lake, examine figures on pages 172 and 186 of the Second Annual Report of the United States G-eological Survey. See Fig. 117 in Gilbert and Brigham's Introduction to Physical Creography. EXERCISE XXIV Glacial Plains {Prairies) Marion Sheet, Iowa 1. Describe the appearance of the land north of Marion. 2. How much is the relief near East Branch Otter Creek? 3. Find the slope per mile of this stream. 4. Describe the valleys of the two branches of Otter Creek with reference to their depth and slope. 5. What do you note about the location and direction of the roads ? 6. Make a profile along the heavy broken line just below the word "Linn," beginning at the 900-foot contour just southwest of the letter L and extending east to the 900- foot contour about halfway between the two w's (hori- zontal scale as on map, vertical scale 1 inch to 200 feet). Take the elevation at each of the 900-foot contours, at the contours on either side of the stream, and at points about halfway between the 900-foot contours. 7. This area was smoothed over with drift dragged by a large ice sheet which passed over it a number of thou- sand years ago. 30 LABORATORY AND FIELD EXERCISES EXERCISE XXV WoEN-DowN Plains A Large Part of the Great Plains 1. Review your notes on "An Old River," Caldwell Sheet, Kansas. 2. See Plate VI in Davis' Elementary Physical Geography. PLATEAUS EXERCISE XXVI YouNfi Plateaus Echo Cliffs Sheet, Ariz. 1. Review your notes already made on this sheet and answer the following questions. 2. What is the appearance of the region each side of Echo Cliffs? 3. What is the height of the region? 4. Find the depth of the canyon of the Colorado River. 5. What do you find concerning the number of streams draining this area? 6. What do you notice about the number and length of the dry canyons ? 7. What do you observe concerning the number of settlements and the location of the trails? 8. In the Second Annual Report of the United States Geological Survey see plates opposite pages 62, 110, 130, 144, 146, 148, and 162. 9 THE LAND 31 exercise xxvii Dissected Plateaus Charleston Sheet, W. Va. 1. Review your notes of Exercise XVI. How do the elevations of neighboring ridges compare? What is the significance of this ? 3. What is the difference in elevation between the low- est and highest points ? 4. What do you notice concerning the location of the roads and the number, size, and location of the villages ? 5. See Fig. 79 in Davis' Elementary Physical Geography. EXERCISE XXVin Old Plateaus Abilene Sheet, Tex. 1. Describe the slope and appearance of the land in the northern third of the sheet. How high is this area ? 2. What additional feature do you find in the central third? 3. These are called mesas. Are they obstacles to travel or are there gaps between them ? 4. Taking the mesa west of Cedar Gap as a type, describe its top and sides. How high above the surrounding land is it? How do other mesas compare with this as regards elevation ? How would you explain these features ? 5. Beginning with the letter G in Cedar Gap, draw a profile along a line extending 2 inches west (horizontal scale as on map, vertical scale 1 inch to 500 feet). Take the elevations at the ends of the line, at the 2000-foot and 2100-foot contours, and at each edge of the top of the mesa. 6. See Fig. 80 in Davis' Elementary Physical Geography. 32 LABORATORY AND FIELD EXERCISES MOUNTAINS exercise xxix Dissected Block Mountains Alturas Sheet, Oal. 1. In what direction do the Warner Mountains extend? How many miles long are they ? How many wide ? 2. What is the nature of the land on either side of these mountains? 3. How high above the surrounding country do they rise? 4. What do you observe concerning the number of streams on their sides? 5. Compare the slope on the eastern with that on the western side at five or six places between Fandango and Eagle peaks. To do this compare the distances from the summit to the 5000-foot contour on each side. 6. The contours bend toward the center of the mountain where crossed by streams, and away from the center between the streams. What does this signify? 7. Are the crests of the mountains smooth and even or notched and uneven ? 8. Make a profile through Cedar Peak along a line extending 3 inches east and 3^ inches west (horizontal scale as on map, vertical scale 1 inch to 4000 feet). Take the elevations at the summit and at each of the heavy contours. 9. See Fig. 128 in Gilbert and Brigham's Introduction to Physical Greography. THE LAND 33 EXERCISE XXX Domed Mountains Menry Mountains Sheet, Utah 1. What is the diameter of Mount Ellsworth? How high above the surrounding country does it rise ? 2. (a) What is the direction of the contours with refer- ence to the summit ? (6) Do the summits of this mountain and the others north of it end in sharp peaks ? (c) In the case of Mount Ellsworth is the steepest slope at the sum- mit or a little way below ? (d) Bearing in mind the obser- vations made, describe the form of Mount Ellsworth. 3. Make a profile along a line running northwest and southeast through the summit, extending to the 6000-foot contour on each side (horizontal scale 1 inch to 2 miles, vertical scale 1 inch to 4000 feet). Take the elevations at the ends of the line, at the summit, and at each of the heavy contours. 4. In Gilbert's Report on the Gteology of the Henry Mountains examine the frontispiece, the figures on pages 19, 23, and 27, and Plates I, II, and III at the end of the book. exercise xxxi Massive Mountains a. The Rochy Mountains in Colorado. Canyon City Sheet, Col. 1. In what direction do the Wet Mountains extend ? 2. What is the relation to these mountains of the valley of the Arkansas River ? How does its valley on the eastern part of the map differ from that on the western ? 3. What effects have the smaller streams had on the slopes of the mountains ? 34 LABORATORY AND FIELD EXERCISES 4. Find Webster Park, just southwest of Royal Gorge. How does this differ from the country south of it ? Huerfano Parh Sheet, Col. 1. What is the height of Blanca Peak? 2. Find Veta Pass on the southeastern part of the map. What is its relation to the streams near ? 3. See Plates I and VII in Davis' Elementary Physical Geography. In Gilbert and Brigham's Introduction to Phys- ical Geography examine Figs. 121, 123, and 124. In Fig. 123 locate the area you have been studying. b. The Rocky Mountains in Montana. Livingstone Sheet, Mont. 1. Compare the summits of the Bridger and Absaroka ranges. 2. In what respects does the valley of the Yellowstone River between Lower and Yankee Jim canyons differ from that farther south ? This valley was probably at one time filled by a lake. EXERCISE XXXn WoBN-DowN Mountains which have again been uplifted Chesterfield Sheet, Mass. 1. If you were standing on the elevation \ mile south- east of Ringville, what would be the appearance of the sky line as you looked around in a circle? Are the hills of so nearly the same height as to form an even sky line, or is the difference between their elevations such as to give a rugged appearance? 2. With the summit of this hill as a center, draw a cir- cle with a radius of 1^ inches. This is to represent the THE LAND 35 sky line for one standing at the center. Make a small cross on the summits of about seven of the principal hills that come nearest the circumference, so chosen as to be scattered as much as possible. Procure a piece of unruled paper 2 inches wide and of the same length as the circum- ference of the circle. Bend the paper till the ends meet. Stand this on the map, making it coincide with the circum- ference. On the outside of the paper at the bottom make dots opposite the marked hills. Put over each dot the height of that hill. Now measure up from each of these dots distances to correspond with the elevations on the scale of 1 inch to 1000 feet. Calculate and measure the distances to the nearest thirty-second of an inch. Mark the limit of each of these distances with a dot. Connect these with a smooth line. With scissors or knife cut the paper along this line, and bend till the ends meet. This represents the sky line as it would be seen from the cen- ter of the circle. Now look again at question 1 and see whether your answer agrees with the profile. Paste this in your notebook. 3. If the valleys were filled up to the level of these hills, what would be the appearance of the region? 4. At one time there existed in New England a mountain system which was worn down to a plain, of which these hilltops are the remnant. The land was then uplifted and the processes of erosion began their work. What evidences of uplift and erosion do you find? 5. Describe the valleys with reference to their width, depth, and slope of banks. In what stage of development are the streams ? 6. In the National Geographic Monograph^ No. 9, " The Physical Geography of Southern New England," examine figures on pages 270, 272, 286, and 287. 36 LABORATORY AND FIELD EXERCISES EXERCISE XXXni Appalachian Ridges Harrishurg Sheet, Pa. 1. (a) Describe the summits of Peters, Second, and Blue mountains, (h) What relation in direction do these ridges bear to each other ? (e) How do their heights com- pare ? {d) Describe their slopes. 2. What is the average depth of the valleys between these ridges ? How far apart are the ridges ? 3. What is the relation of streams like Clark and Stony- creeks to the ridges ? What is the relation of the Susque- hanna River to the ridges ? 4. At what points is the Susquehanna narrowest? How may this be explained? Would the same explanation apply to the presence of the ridges and valleys? 5. What do your observations made under 1 (c) suggest concerning the former condition of the country ? 6. Where are the settlements located? 7. Make a profile from the letter B in Blue Mountain to the letter d in Third Mountain (horizontal scale as on the map, vertical scale 1 inch to 1000 feet). Take the elevations at the summits of the ridges, at the streams, at the 500-foot and 600-foot contours in the valley of Fishing Creek, and at the 400-foot and 500-foot contours in the valley of Stony Creek. 8. In the National G-eograpMc Monograph, No. 6, " The Northern Appalachians," examine figures on pages 170 and 183. THE LAND 37 VOLCANOES exercise xxxiv Young Volcan-io Mountains Shasta Special Map, Cal. 1. How higli is Mount Shasta above the sea level? How high above the surrounding country? What is its general form? 2. As you pass from base to summit, where are the slopes steepest? 3. What evidences do you find of the beginnings of erosion ? 4. What do the white patches with blue lines found near the summit represent? How many are there? How large is the largest? What forination is found at their lower ends ? What have their source just below these ? Why ? 5. What is indicated by the brown lines in the center of Hotlum Glacier? 6. How many minor summits do you find? Shasta Sheet, Cal. 7. Make a profile along a line through the top of Mount Shasta, extending northwest and southeast to the 5000-foot contour on each side (horizontal scale as on map, vertical scale 1 inch to 4000 feet). Take the elevations at the ends of the line, for every two thousand feet, and at the summit. For the profiles of this and the next two exercises use a piece of unruled paper 10 by 6 inches. Draw the base line for the Shasta profile 4' inches from the top of the paper, parallel with the shorter dimension. 8. In the National Geographic Monograph, No. 8, " Mount Shasta," examine figures on pages 243, 244, 258, and 260. 38 LABORATORY AND FIELD EXERCISES exercise xxxv Matubbly Dissected Volcanic Mountausts Mount Taylor Sheet, N.Mex. 1. How does Mount Taylor compare with Mount Shasta as regards {a) elevation above surrounding country? (I) steepness of slopes? (c) regularity of form? {d) diameter at base ? 2. Make a profile along a line through the summit, extending northwest and southeast to the 8000-foot con- tour on each side (scales as in the previous exercise). Take the elevations at the summits and at the heavy con- tours. Draw the base line 3 inches below the Shasta line. exercise xxxvi Old Volcanic Mountains. Volcanic Necks Mount Taylor Sheet, N.Mex. 1. Describe Cabezon Peak as regards [a) height above surrounding country ; (h) slope ; (c) form ; {d) diameter at base. 2. Make a profile along a line from the summit, extend- ing eastward just over the top of the letter C to the 6000- foot contour, and westward to the 6000-foot contour (scales as in the two preceding exercises). Take the elevations at the ends of the line, at the summit, and at the 6400- foot and 7000-foot contours. Draw this line % inch from the bottom of the paper. 3. Make a written comparison of these three profiles and paste the paper in j^our notebook. 4. See Figs. 8 and 9 in Physiographic Types, Folio IT. THE LAND 39 exercise xxxvii Lava Plateaus Modoc Lava Beds Sheet, Cal. 1. What two very different kinds of land forms do you find represented on this map ? 2. How wide are the lava beds ? What is their average elevation ? 3. What do you notice concerning the course of the Pit River? 4. These valleys were filled with liquid lava, which spread out evenly and cooled in the position in which it is now found. Do you find any evidence of the effect on the streams that might result from the blocking of the valleys by such an outpouring? EXERCISE XXXVIII A CBAtEK CONTAINING A LaKE Crater Lake Special Map, Ore. 1. If one were standing on the summit of the Watch- man and looking east, what would be the appearance of the land surrounding the lake ? How many feet below the Watchman is the surface of the lake ? How would the sloj)e to the west compare with that to the east? 2. How wide is the lake? How deep? Has it any outlet? 3. How high above the surrounding country is the ridge around the lake? 4. Examine the streams and valleys on the southern slope to ascertain what relation they bear to the ridge sur- rounding the lake. Do you think that the streams in their present condition could have brought about this relation ? 40 LABORATORY AND FIELD EXERCISES 5. The feature referred to in 4 indicates that the moun- tain was once much higher than now, and that its upper part has disappeared, probably sunk, cutting off these canyons part way down the slope. Compare this map with the Shasta Special. If you sup- pose that part of the map covered by the lake to be filled in with contours coming to a point, as in Shasta, with increasing slope, you will have restored in a general way the former volcano, which was probably of about the same size as Shasta. 7. Copy in your notebook the section at the bottom of the map, but making it only half as large. 8. In the Annual Report of the Smithsonian Institution for 1897, study the plates between pages 379 and 381. In Physiographic Types, Folio II, see Figs. 10 and 11. In Gilbert and Brigham's Introduction to Physical Geography, see Figs. 152 and 153. exercise xxxix Identification of Land Forms Determine what type of land form is represented on the maps furnished you. In studying the map note {a) scale and contour interval, (b) elevation, (c) relief. First deter- mine the general character of the country, whether that of a plain, plateau, mountain, or some other form. Then, by a more careful study, ascertain in what stage of develop- ment the land form is. If a plateau, is it young, dissected, or old ? If a mountain, is it sharply dissected with steep slopes, or is it subdued with gentle slopes? If there is a river on the map, is it young, mature, or old? Is a flood plain present? THE LAND 41 exercise xl Study of Minerals To THE Teacher. Before beginning the study of individual minerals each of the features suggested in the accompanying out- line should be studied by means of the specimens, the pupils first noting the differences and then being told the names applied to the various characteristics. After the terms to be used are under- stood, each mineral may be studied as suggested below. To THE Pupil. Describe each of the minerals furnished you in accordance with the following outline, writing the description in your notebook. 1. Form. Crystalline or amorphous. 2. Structure. Granular, compact, foliated, banded, fibrous. 3. Cleavage. Perfect or imperfect. Cubic, rhombohedral, basal. 4. Hardness. Refer to scale. 5. Specific gravity. Determine by dividing weight in air by loss of weight in water. 6. Luster. Metallic, vitreous, resinous, pearly, silky. 7. Transparency. Transparent, translucent, opaque. 8. Streak 9. Color. 42 LABORATORY AND FIELD EXERCISES EXERCISE XLI Study of Kocks Describe each of the rocks in accordance with the fol- lowing outline. . 1. Stratified or unstratified. 2. Crystalline or amorphous. 3. Of what minerals composed. (a) relative amount of each ; (h) color of each ; (c) size and form of grains ; (d) how held together. 4. Prevailing color or colors of rock. To what due. 5. After all the specimens have been studied, tell how you can distinguish between igneous, metamorphic, and sedimentary rocks, from the features suggested in 1 and 2. 6. Identify the unlabeled specimens of rocks and min- erals furnished you. When you have named a specimen, compare with your written description of that mineral or rock to ascertain if your identification is correct. FIELD WOKK {see Appendix a) EXERCISE XLII Weathering 1. Examine buildings, monuments, quarries, ledges, stone walls, and bowlders for evidence of weathering. 2. How does the weathered surface in each differ from a freshly exposed surface ? 3. What agents may have been at work to bring about these changes? 4. Do you notice any difference in the rapidity with which the different kinds of rocks weather ? Does weath- ering take place evenly in all parts of the exposed surface THE LAND 43 of the same rock? Look around your locality to see if you can find results of this differential weathering on a larger scale. Refer to your text-book and find examples, in other parts of the world, of different shapes of the earth's surface due to the wasting away of the land, such as the Catskill Mountains, the ridges of Pennsylvania, and others. 5. What becomes of the weathered material? Is this motion of the land waste continuous ? What are some of the forms that this waste assumes on its journey? Of what use is it to mankind meanwhile ? What will the final result be if this wasting away continues for long ages? What forces may interfere with this result? 6. In order to obtain some idea of the rapidity with which weathering agents work, ascertain if you can, by inquiry, how long the surfaces you are examining have been exposed. 7. In a railroad cut or in a quarry compare the color of the material at the top with that of the material at the bottom. 8. Look to see if you can find any place where the roots of trees are aiding in breaking up the rocks. Describe what you find. 9. Name the agents of weathering, evidence of whose action you have actually seen in the field, giving examples of each. exercise xlhi Stream Action 1. Study the current of a small stream. On which side of a curve is the stronger current? Make a diagram in your notebook to show this. 2. What is the action of the stream on the bank nearest the current? What is taking place on the opposite bank, 44 LABORATORY AND FIELD EXERCISES where the current is weaker? Compare the slope of the two banks. 3. Examine other parts of the stream to see if you can find more advanced stages of this process. In this con- nection study a topographic map of the lower Mississippi River, or refer to illustrations and discussion in the text- book. 4. This action is known as lateral erosion. Do you find any evidences of vertical erosion anywhere in the stream? How does the velocity of the stream where vertical ero- sion is most prominent compare with that where lateral erosion is taking place? Explain then the conditions, iis regards swiftness of current, under which each kind of erosion occurs. For an example of vertical erosion look up a discussion of the Colorado River. 5. Where lateral erosion is taking place, does the stream tend to be crooked or straight? What is the appearance of the land on either side of the stream where lateral ero- sion is occurring? What is the width of the flood plain? Of what kind of material is it composed? Describe the material as regards shape and arrangement. For examples of flood plains look up the Mississippi, Rhine, and Nile rivers. 6. Do you find in the stream alternations of rapids with reaches of quiet water? In the reaches what determines the depth to which the .channel is cut? This is known as a local base level. What is the final base level of a stream ? What do you note concerning the strength of current in these reaches ? These are said to be graded, that is, there is just sufficient slope to allow the current to wash along the waste furnished. When may the whole stream be said to be graded? THE LAND . 45 7. Do you find the stream actually carrying any sedi- ment? (Observe just after a rain.) At other times do you find any motion of the sediment along the bottom of the stream? What effect will the motion of these particles have on the- bed of the stream? Do you find any large pebbles in the stream which the current cannot move? How do you account for their presence here? What is the source of the material which the stream is carrying and depositing? Note the amount of erosion that the stream you are studying has accomplished. Read about the amount done by any large river system. Which indi- cates the larger amount of weathering and erosion, a river with a steep narrow gorge like that of the Colorado, or a broad open valley like that of the Mississippi ? 8. In broadening valleys what part do weathering and erosion play respectively? If these processes continue for long periods, without the intervention of other forces, what will be the final form of the surrounding country? In what stage of this cycle should you judge the stream you are studying to be, — that is, does it seem to have nearly reached this final stage, to be fairly on the way towards it, or to be only just beginning ? Look up examples of each of these stages in other parts of the world. 9. After a heavy rain examine the gullies by the road- side for examples of erosion and deposition. Describe what you find. Make a map of the area. 10. Write a brief account of what you have learned regarding stream action. 46 LABORATORY AND FIELD EXERCISES EXERCISE XLFV Drift 1. Examine both stratified and unstratified deposits. Which are the more common ? What is the general form of the surface in each case ? 2. In the unstratified deposit describe the material found as regards shape, relative size, and arrangement. Could this formation have been made by water? Give reasons for ' your answer. 3. Do you find any rock fragments unlike the rock of the neighboring ledges? Are the fragments all of one kind or quite varied in composition? 4. How do the shape and arrangement compare with those of the materials found in the flood plain ? How do you explain the difference? 5. Can you find any fragments that are scratched? Ascertain the significance of this. Can you find any of the underlying rock that is scratched and rounded? In what direction do these scratches extend? Do they all extend in the same direction? Is the rock deeply weath- ered? What inference do you draw regarding the time that has elapsed since these rocks were scoured by the glacier ? 6. In the stratified deposit note the general form of the surface and the shape and arrangement of the fragments composing the deposit. How do you explain the differ- ence between these and the unstratified deposits? 7. Do you find stratified and unstratified material in the same bed? 8. How many different surface forms of glacial deposits can you find? Visit any drumlins (see topographic map, Sun Prairie, Wis.), eskers, or kames that may be found in THE LAND 47 your neighborhood, noting their form and size and the nature of the material composing them. 9. How does the thickness of the drift at different places compare ? 10. Are the streams of the surrounding country gener- ally smooth flowing, or are rapids common? Are ponds found in the neighborhood? Of what stage of develop- ment are these features evidence? 11. Look for drift bowlders. Note their size and abun- dance. Are they like the rocks of the immediate vicinity? 12. If near the southern limit of the glacial belt, visit the terminal moraine. Note its general form and size, the direc- tion in which it extends (What relation does this bear to the direction of ice movement?), depth of deposit, and arrange- ment, composition, and shape of the fragments composing the moraine (see topographic map, Charlestown, R.I.). Additional Field Woek The field work here suggested is such as may best be done in the fall to serve as a foundation for later work. The study of weathering and stream action may be carried on in almost every locality, and the study of drift in the northeastern part of the country. The nature of further field work must depend upon the locality. An attempt may be made to explain and classify the general topographic features of the vicinity, and in some cases it may be profit- able to make a topographic map of a small area. If one is situated in a glaciated region, a trip may be made to a glacial deposit for the purpose of ascertaining how many kinds of rocks may be found. If the instructor can learn the location of the nearest outcrop northward 48 LABORATORY AND FIELD EXERCISES of each kind of rock, this will tend to give more definite impressions regarding the work of the glacier. If one is near the sea or a large lake, observations may be made on the work of the waves in wearing back the coast and of the currents in washing away the loose mate- rial and in forming beaches and bars. The folios of the United States G-eologic Atlas contain very detailed information regarding the geologic and geo- graphic features of the region treated, and from them a large number of field trips may be planned. One may ascertain whether the folio for any specified region has been published by addressing the Director of United States Geological Survey, Washington, D.C. The price of each folio is 50 cents. CHAPTER III THE ATMOSPHERE (see Appmidix A) exercise xlv Weathek Observations Copy the table given below in your notebook, extending the columns to the bottom of the page. Between eight and nine o'clock each morning make the observations called for and put the record in your notebook. 11 3 Press iTKE TEMPERATriiE Clouds (amount in tenths) Prkcipita- TIOX Winds a II i to E 3 o £ < o o u CD k The record of the force of the wind may be kept in accordance with the following scale proposed by Professor M. A. Ha.zen of the United States Weather Bureau. 0, calm ; 1, light, just moving the leaves of trees ; 2, moderate, mov- ing branches; 3, brisk, swaying branches, blowing up dust; 4, high, 49 50 LABOKATORY AND FIELD EXERCISES blowing up twigs from the ground, swaying whole trees ; 6, gale, break- ing small branches, blowing loose bricks from chimneys; 6, hy.rricane or tornado, destroying everything in its path. When the above observations have been taken for a month, the following exercise is to be worked out. Copy on a piece of unruled paper the table given on page 51, using care to keep the dimensions the same as those found in the table. The distances on the lower part of. the line at the left are made to correspond with the scale on a barometer. The line a little above this, extending across the page, represents the freezing point, and dis- tances are measured above and below this line to corre- spond with the scale on a thermometer. Above this, fractions of an inch are measured off to represent the amount of rainfall. On the table on page 51 are to be plotted the various weather conditions for the month, for which you will need three colored pencils, — red, blue, and yellow. Rainfall. By means of the scale at the left measure down for each day from the top line a distance correspond- ing with the amount of rainfall for that day. (Remember that you will get the amount for any given day from the records of the next day.) Fill in with black the part of the columns included within these distances. Cloudiness. Measure down from the same line distances to represent the cloudiness, allowing the distance to the freezing-point line to represent a cloudiness of \^. Thus, if the amount of cloudiness were -^-^, you would measure down j-\ of the distance to this line. Mark off the pro- portionate distance for each day and fill in down to these points with yellow. Temperature. Put a dot in each column opposite the reading on the left-hand line that corresponds with the THE ATMOSPHERE 51 o5 g s s s § 8 s s CI S g m S- t- o lO "* CO (M S o • o CO t- «o la "* w