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DRY FARMING CONGRESS. 



This slide shows the precipitation in the Great Plains as a whole for 

 each 3'ear since the earliest available records, namely, about 1875. The 

 records obtained in this diagram were compiled by Prof. Chilcott and my- 

 self from the records of the Weather Bureau. Now you will notice the 

 first year shown on the diagram is the year 1877 and the last year the 

 year 1907. There are records for two years more which do not appear to 

 come out. The irregular lines, or horizontal lines, show the precipitation 

 in inches, and the curveS will show the variation from year to year in 

 the total precipitation in the Great Plains. In the early part of the rec- 

 ord we have only four states to go on. Later we had six, and later we 

 had, of course, a great many more records. In the latter part — for the 

 last twenty years — we feel that this record is very representative of the 

 rainfall of the Great Plains, because these stations were so chosen as to 

 be representative, geographically, both east and west and north and south. 

 In other words, if we had a station in the eastern part of the area we had 

 another one in the western part of the area, so that they were equal dis- 

 tance from the center. The station in the south and the station in the north 

 would likewise correspond. The heavy, solid curve represents the annual 

 precipitation for the Great Plains Area as a whole and in 1891 you will 

 see the precipitation was especially high, an average of over 24 inches for 

 the whole area. In 1905, which was a year of excessive rainfall, it aver- 

 aged, for the Great Plains Area as a whole 27 inches; and in 1906, rep- 

 resented by this point, 23 inches. But for the year 1907 we have for the 

 total precipitation of the area a little less than 18 inches. 



Now I would like to call attention to the condition as it exists at the 

 end of 1907. You will notice in running back over this curve there are 

 only three cases, here, here and here, in other words, 1890, 1893 and 1894, 

 where the precipitation is as low as it was during the year 1907. In other 

 words, instead of having an increased rainfall we have arrived at a condi- 

 tion for a low precipitation, which has only been equaled three times in 

 the history of the area. So that our situation at the present time cor- 

 responds with the situation here. That is, every year following a heavy 

 precipitation — you see we had heavy precipitation in 1906, very heavy pre- 

 cipitation in 1902, with low precipitation .in 1903. So the indications are 

 that next year we will have a heavy rainfall like that, in whch case the 

 low rainfall of the past year will not be seriously felt. I mention this 

 point simply for the purpose of showing that there is no foundation in 

 fact for the statement which has been made so frequently and so widely 

 spread, that the climate of the Great Plains, as far as precipitation is 

 concerned, is permanently changed. There is another point from which 

 I think we can get instruction from this diagram. This heavy horizontal 

 line here represents the average precipitation for the first ten years; this 

 horizontal line represents the average precipitation for the second ten 

 years; and this for the third ten years. You will notice, then, if we di- 

 vide the precipitation into ten-year periods and take the average for the 

 periods that the precipitation during the past ten years, 1895 to 1905, ex- 

 ceeds the precipitation for the previous ten years, which includes the great 



