50 



METEOROLOGICAL CONDITIONS. 



The meteorological observations made at the station show great changes in 

 temperature during the day. I have been told by several old residents that they 

 never experienced a summer similar to that of 1873. The rainy period of the summer 

 is looked for about the ist of July, to last only a few days. This year it was noted 

 that from July 28th to August gth there was no day without rain, accompanied by 

 thunder and lightning. The prevailing winds were from the northeast or southeast, 

 commencing at 10 or 1 1 o'clock a. m., and increasing in force until 2 or 3 o'clock p. m. 

 Then clouds came up from the southwest or west, bringing much rain, thunder, and 

 lightning. It was generally clear again by 1 2 p. m.; but I found the air so very undu- 

 lating, and the stars on that account so faint, that I was sometimes obliged to suspend the 

 observations. It is probable that the temperature of the higher regions of the air was 

 affected by the vicinity of the mountains, and after a rain changed very rapidly, while 

 the lower strata remained under the same conditions. 



The following table shows the general direction of the wind at 7 a. m., 2 p. m., 

 and 9 p. m., giving the mean or prevailing direction of the wind for three hours before 

 and three hours after the given time ; also the estimated force of wind for the same 

 time. The last column gives the general appearance of the sky, and needs no further 

 explanation. It shows under what particularly unfavorable circumstances the obser- 

 vations were made: 



DESCRIPTION OF OBSERVATORY AT COLORADO SPRINGS, COLORADO TERRITORY. 



As soon as the monument was built, a solid framework, 8 by 10 feet, was con- 

 structed, and a large wall-tent put over it. There was an opening in the tent for the 

 meridian-line ; this was closed, when necessary, by a fly. During heavy winds the 



