SUMMER HOT WINDS ON THE GREAT PLAINS. 
337 
etc.; and this feature of the hot winds in summer over the 
eastern slope of the Rocky mountains had been overlooked 
in previous discussions. 
The hot winds are likely to occur between May 15 and 
September 15, but are most frequent during July aud Au¬ 
gust, and the thirty-five periods of which we have records 
are distributed as follows: May 1, June 4, July 16, August 
13, and September 1. The length of time during which a 
period of these winds is likely to prevail varies from a few 
hours to three days. Sometimes, but rarely, two or three 
of these periods of hot winds follow each other in rapid 
succession. Some observers have only noted these winds 
during the day; others have noted them continuously for 
twenty-four hours, and even longer, while others have ob¬ 
served or rather experienced them only at night, and they 
have often been noted as continuing into the night. During 
the hot winds in Texas July 18, 1886, the temperature at 
9:21 p. m. (local time) stood at 96°, with wind eight miles 
per hour, from the south. 
The hot winds are always referred to as extremely dry. 
Although very few hygrometric observations have been 
made in connection with them, yet those on record confirm 
the general statement regarding this condition. Prof. F. H. 
Snow, of the University of Kansas, recorded a relative 
humidity of 7 per cent, at Lawrence, Kansas, and the ob¬ 
server of the Signal Service at Leavenworth, Kansas, recorded 
at 5:48 a. m. (local time) 90; 9:48 a. m., 52; 1:48 p. m., 17; 
5:48 p. m., 17, and 9:48 p. m., 22 per cent., September 12, 
1882. On September 13, 1882, the observer at Leaven¬ 
worth recorded the relative humidity at 5:48 a. m. (local 
time), 45; 9:48 a. m., 41; 1:48 p. m., 20; 5:48 p. m., 14, 
and 9:48 p. m. 20 per cent. On the 14th, 5:48 a. m., 50; 
908 a. m., 25; 1:48 p. m., 13; 5:48 p. m., 18, and 9:48 p. m. 
44 per cent. On the 15th, 5:48 a. m., 63; 9:48 a. m., 46; 
1:48 p. m., 29; 5:48 p. m., 28, and 9:48 p. m. 51 per cent.; 
after which there was as decided an increase in moisture as 
there was a decrease after the lltli and the morning of the 
