What to use. Cross-section paper and the data given on page 143 and in figure 76 of the text.

What to do. 1. Note the relative locations of the three cities as shown on the map on page 147. By use of the mean monthly temperature data (p. 143) and the cross-section paper above, prepare a curve showing the temperature variation for each city for the full year. Each line should be labeled. Use different colors if possible.

EFFECT OF A LARGE BODY OF WATER UPON THE TEMPERATURE OF THE REGION NEAR IT (XII-1)

The problem. Certain cities frequently are advertised as desirable summer resorts when much is made of the nearness to lakes or oceans. What is the real or supposed influence which these bodies of water exert on the temperature?

Questions. Which of the three cities referred to has the lowest average and which the highest average temperature? How are the summer temperatures of the three places related? the winter temperatures? Which place has the greatest annual variations in temperature? Could the lake be responsible for the differences in temperature of the three places? How?

Suggestions for report. Write a brief statement showing how lake or ocean cities differ in temperature from inland cities.

Reference work. Read sections 158 to 166.

Optional problems. Compare temperatures at a given point in California and at points in approximately the same latitude in the Rocky Mountains, Central States, and along the Atlantic coast. Study the temperature curves on pages 142 and 149 and see whether temperature in both cold and hot waves seems to be influenced by lakes. Why are there many productive peach orchards on the east shore of Lake Michigan and few or none on the west shore?

WATERWAYS AND HARBORS (XIII-1)

The problem. Most young persons will be surprised when they look at the map on page 153 of the text to see the number and extent of navigable rivers in the United States. The harbors, which cannot be well shown on such a map, are equally numerous and equally important. A study of some one waterway system should prove of interest.

What to use. The map on page 153 of the text and maps or charts of the nearest waterways or ports. These may be had at small cost, or free, from the proper government authorities, as follows: Coasts of the United States, U. S. Coast and Geodetic Survey, Washington, D. C.; Great Lakes, U. S. Lake Survey Office, Detroit, Mich.; Mississippi River, Mississippi River Commission, St. Louis, Mo.; Prevention of River Floods, Ohio River Valley Flood Commission, Dayton, Ohio.

What to do. 1. The conditions and facts of different waterways vary so largely that the work to be done cannot be outlined specifically. The work should include a study of the extent and use of the watercourse, the channels, depths, obstructions, lighthouses, buoys, fog signals, and wharves and other facilities for loading and unloading.

Questions. Is water transportation of much importance in the United States? What are the features most desirable in a river for use as a means of transportation? What are the requirements of a good harbor? What are "Eads jetties," and how and why were they constructed? What were the causes of the Ohio River Valley flood of 1913, and what means are being used to guard against a repetition of such floods?

Suggestions for report. Write a brief statement of the nature, extent, and use of any particular waterway you have studied.

Reference work. Read sections 167 and 168 and any printed descriptions of the waterways of your part of the country.

Optional problems. With a leading product as a basis for discussion,-as cotton, wheat, coal, iron, or lumber,-indicate the points to which the major part of the output is shipped and the chief routes of shipment, and thus show the extent to which water enters into the transportation of this product.

LOCAL IMPORTANCE OF WATER TRANS

PORTATION (XIII-2)

The problem. It is likely that every community in the United States uses some articles which have been carried in part by water transportation. Thus, to an extent, every community is partly dependent upon water transportation.

What to use. Maps and records regarding your nearest harbor or waterway; reports of the United States Department of Commerce and Labor dealing with kinds and quantities of materials shipped by water from this harbor or on this waterway; reports or data from individual steamship companies regarding number of boats used, amount, nature, source, and destination of goods.

What to do. 1. Study the records listed above. From local merchants secure an estimate of the proportion of goods used which are shipped by water and the proportion shipped by rail.

Questions. If all water transportation to your community were discontinued, would the community suffer seriously? What kinds of goods are shipped more economically by water? by rail? How does time involved in shipping by water compare with time used in rail shipping?

Suggestions for report. Prepare a list of locally used materials which were shipped by water and give the source of each one.

Reference work. Read sections 169 to 172. Consult state and national records regarding kinds and quantities of imported and exported materials.

Optional problems. What influence did waterways have upon the establishment of New York City? of Philadelphia? of San Francisco? of New Orleans? of St. Louis? of Pittsburgh? of Seattle? What cities or towns of your immediate community are there whose location was affected by waterways?