12 



ice, making it sufficiently uncomfortable to restrain the ardor of an observer from 

 extending his observations into the small hours of the night. From the experience of 

 this season, and that of many others which I have undergone in former years in 

 astronomical work, both on the plains and in the mountains, I am of the opinion that 

 the best time of the year (so far as the weather is concerned) for astronomical observa- 

 tions in the Territories and the far Western States occurs in September and October. 

 They are the months that fall between the rainy season of the summer and the stormy 

 weather of the winter. 



The following table shows the direction of the wind, and the estimated force, from 

 7 a. m. to 7 p. m. and from 7 p. m. to 7 a. m. The weather was clear all the time. 

 Such an atmosphere, at an elevation of 6,000 feet, could not be otherwise than favor- 

 able for astronomical work. 



(4.) DESCRIPTION OF OBSERVATORY. 



A large wall-tent drawn over a framework formed the observatory. The open- 

 ing for the meridian-line was furnished with a flap and curtains ; the former served to 

 protect the instrument from the weather when not in use, and the latter to keep off the 

 wind and dust while observing. Here, and at other stations previously occupied, the 

 opening for the meridian-line in the observatory was entirely unobstructed. Subse- 

 quently it was found to be an improvement to retain the ridge-pole (which commonly 

 interferes but little with the completeness of the observations) as a support against the 

 violent winds so prevalent in the country in which our operations are conducted. The 

 tent was furnished with all the appliances of a field and temporary observatory, such 

 as stools, stands, tables, and the like, and nothing was wanting as to equipment for first- 

 class field-work. The Western Union Telegraph Company furnished the line and 

 other facilities for this station. Mr. Bates, one of the operators employed at the 

 Cheyenne office, was assigned to do the telegraphing; and when business did not per- 



