Clayey soil is best for holding moisture and sandy soil is poorest. Nearly all of the soil of South Dakota is made from fine clay, and thus is the best possible kind to hold and use the water.

Total Precipitation. The total precipitation (rain together with snow and sleet melted and treated as rain) each year for the eastern half of the state averages 22 3 inches, and for the western half 17.3 inches.

CLIMATE PERMANENT. There is a very widespread belief that the climate of South Dakota is changing, getting warmer and receiving more rain. The weather records, carefully preserved, do not show any such change. The longest reliable records in the state are at Yankton*, extending back to 1873, and for the north central West at St. Paul, Minn., beginning in 1836.

The three years of heaviest rainfall at these stations were as follows:

Yankton, 40.95 in., 1881; 37.15 in., 1875; 35.21 in., 1883.

St. Paul, 49.69 in., 1849; 39.16 in., 1881; 38.14 in., 1865. The ten-year period having the greatest rainfall was 1865-1874 at St. Paul, averaging 32.32 in.; 1875-1884 at Yankton, averaging 28.64 in. It should not be inferred that rainfall was greater in pioneer

* There are a few records at Fort Randall extending as far back as 1857, and at Fort Sisseton from 1866 to 1889, but these records are not complete.

years, excepting for the year mentioned, for the highest five-year period at St. Paul was 1902-1906, averaging 33.54 in.; at Yankton, 1905-1909, averaging 29.06 in.

A diagram showing the rainfall and temperature by years shows no general increase or decrease either in heat or moisture. A diagram of that of Huron is given here because the records there are the most reliable in the state, all of them having been made by the same government expert, Mr. S. W. Glenn.

VERIFICATION. Every weather record in this chapter has been obtained from the United States Weather Bureau.

QUESTIONS

SEASONS. Name the seasons. Briefly describe each. From the list showing the dates of killing frosts, find the city nearest your home and the average length of true summer weather.

TEMPERATURES. What is the average annual temperature of the state? Compare the temperatures in the western half with those in the eastern half. From the table find the warmest portion of the state; the coldest. What is the coldest month? What is the average temperature then? What do the lowest temperatures for the state during the month average? For how long at a time do these extreme temperatures prevail? What is the warmest month? What is its average temperature in South Dakota? What is said of extreme temperatures? Note the table showing average temperatures throughout the year. Which city of the list has the warmest January and coolest July? Compare the South Dakota cities with St. Paul.

WINDS. In what wind zone is South Dakota? The air over this state has usually come from where? What is the source of the moisture?

What kind of weather does

CYCLONES AND ANTICYCLONES. the cyclone bring? The anticyclone? How frequently do they occur? TORNADOES. Describe the tornado. In what kind of a general storm does the tornado occur? Why do they occur so rarely in South Dakota?

CHINOOK WINDS. Describe these winds. Of what special value are they in winter, particularly on the western plains?

BLIZZARDS. Describe the blizzard. What can you say as to their frequency? Why are they less dreaded than formerly? What common error is there concerning Dakota winds? What is the average hourly rate at Pierre? Huron? Rapid City? Yankton? Minneapolis? Duluth? New York? Chicago? Why do prairie winds seem more severe than they really are?

WIND VELOCITY. What common error is there concerning Dakota winds? Compare the government records at South Dakota stations with those at Minneapolis and other cities. The high elevation at which the instruments are placed in Chicago and New York in part explains the high velocity there. Why do prairie winds seem more severe than they really are?

RAINFALL. Is there enough rainfall for farming in South Dakota? What is the effect of a dry season now as compared with its effects in earlier years?

RAINY SUMMERS. Compare the rainfall at Yankton with that of Naples. Compare conditions for farming in the two regions. What advantage has Yankton as shown in the diagram?

A FAVORABLE COMPARISON. Compare the amount of rainfall during the five growing months at South Dakota cities with those of the cities around the Great Lakes. Compare the average for the state with that for Michigan. What conclusion may we form?

REGULARITY OF RAINS. Compare the frequency of dry summers in South Dakota, at least in the eastern half, with that of the Great Lakes states. Which is the critical month for rains? Less than two inches of rainfall in June usually has what effect on the crops? How many such dry months are shown in the table for Chicago? Buffalo New York? Aberdeen? Yankton?

PLANT COVER. What can you say as to the importance of preventing evaporation? What is the great value of groves and

forests?

MODERN DIVERSIFIED FARMING. What is the effect of cultivating the soil upon evaporation? Show that the effect is the same as if it increased rainfall. Show the importance of mixed farming.

SOILS AND MOISTURE. Discuss the ability of different kinds of soils to retain moisture. What kind of soil covers nine-tenths of South Dakota? What is the average annual precipitation for the eastern half of the state? For the western half? From the table find the city nearest your home and make a diagram showing the rainfall by months.

CLIMATE PERMANENT. What can you say as to the permanency of climate? What do the weather records at Yankton and St. Paul show? Study Figure 20. The temperature and precipitation lines are higher some years and lower other years, but does that diagram show any tendency for them to continue to move either higher or lower?

VERIFICATION. From what authority have the records of this chapter been obtained.

EXERCISES. From the table showing precipitation find the city nearest your home. Make a diagram showing the average rainfall by months. At a great many places in the state there are co-operative observers of the United States Weather Bureau If there is one near where you live you can get temperature and rainfall statistics from him.

CHAPTER IV

INDUSTRIES AND INSTITUTIONS

Pioneer Privations and Present Prosperity. Looking over old files of newspapers, published between 1860 and 1880, one will find such topics as "Famine in Kansas," "Failures in Dakota," and "The Poor Farmer of the Northwest." Those pioneer days of the dugout, and of lonesomeness and suffering, are now happily in the past, and no parts of the world enjoy such a steady prosperity as these rich agricultural north central states. As already stated, South Dakota for years has been, according to population, the richest state in the Union and each year produces the most new wealth.

Million Dollars

80

70

60

50

40

30

20

10

1900

1901

1902

1903

1904

1905

1906

1907

1908

Fig. 29. Bank Deposits in South Dakota. Note the steady increases.

In our sudy of the surface of South Dakota, we noticed the clays of the glacial drift east of the Missouri river and the fine mud deposits in ancient shallow seas to the west. When covered with vegetable mould these make the richest soils known. In the chapter on climate we noticed the abundance of rain during the

growing months. The combination of the fertile soil and favorable climate and an industrious and thrifty class of people explains why this is the "Land of Plenty."

One of the best possible evidences of the steady growth in prosperity is the amount of money deposited in the banks of the state. Note the increase from year to year.

Fig. 30. The value of new wealth produced in South Dakota.

Corn is King. Corn is the principal crop of the United States and also of South Dakota. Most of the corn produced in this state is raised in the southeastern part, though it is successfully grown in every portion.

"In a report of the United States Department of Agriculture issued November 8, 1909, South Dakota's yield of corn per acre is shown to be two-tenths of a bushel greater than that of Iowa. South Dakota stands second among all the great corn states in the amount of yield per acre, a fact that signifies much when one considers