290 Kansas Academy of Science. 



certain that there had been no change in the general high velocity, 

 for an altitude of 50, 60 or 100 feet, although the trees would re- 

 strict the velocity of the wind near the ground. In his pamphlet 

 just issued he states that "an examination of the wind records in 

 Kansas and Nebraska show that the last fifteen years have not been 

 quite so windy as the fifteen years previous, but that it is not safe 

 to assume that a permanent decrease in the wind velocity has taken 

 place." My own records of the wind velocity began on July 1, 

 1872, when an excellent recording apparatus was installed upon the 

 roof of the north dome of the main building of the University of 

 Kansas, 105 feet above the ground, the ground itself being 250 feet 

 above the broad valley of the Kansas river. This apparatus has 

 been carefully kept in order under my personal direction during 

 the entire 34| years, and its results have been compared with, and 

 corroborated by, those of a standard anemometer of the signal serv- 

 ice pattern, which for fifteen years was in operation at the same 

 elevation. If we adopt the method of comparison used by Doctor 

 Moore in his rainfall statistics, and divide the thirty-four years 

 into ten-year sections, we have the following results : 



The average annual wind run of the first ten years (1873-'82) 

 was 138,052 miles; of the second ten years (1883-'92), 131,040 

 miles; of the third ten years (1893-1902), 122,012 miles; of the last 

 four years (1902-06), 100,212 miles. But, as stated in regard to 

 the rainfall, it seems to be a more satisfactory method of compari- 

 son to divide the entire period into two equal parts. By this 

 method we find the average annual wind run of the first seventeen 

 complete years (1873-89), to be 134,389 miles, and of the second 

 seventeen years (1890-1906), 119,252 miles. This gives an average 

 reduction of 15,137 miles per annum for the second half of our pe- 

 riod of observation as compared with the first half. Stated in an- 

 other way, the average velocity of the wind for the first seventeen 

 years was 15.34 miles an hour, while for the second seventeen years 

 it was only 13.61 miles an hour, giving a reduction of nearly twelve 

 per cent. 



It thus appears that the observations of nearly forty years, 

 made continuously by and under the direction of the writer, indi- 

 cate a gradual change in the climate at Lawrence, Kan. And as 

 this locality presents a typical illustration of the climatic condi- 

 tions of eastern Kansas, it is safe to infer that the same changes 

 are taking place over the entire region of which it forms a part. 

 The rainfall and atmospheric humidity have increased, and the 

 wind velocity has decreased. The change in the rainfall and wind 



