REPORT OF COMMITTEK ON OBSERVATORIES lOI 



the vicinit}^ of the higher mountains, such as the San Francisco 

 peaks, etc. In general the clouds covered only a part of the sky, 

 and their drift was slow. Obsen^ations were frequently interrupted 

 by them. During the middle of the day the cloudiness increased, 

 and thunder storms followed. Late in the afternoon it would clear 

 and the nights were generall)' cloudless. 



As a result of these unsettled conditions it was not expected that 

 the seeing would be at its best, and during my stay Mr. Lowell did 

 not regard it so. To me it appeared onh^ fair. At no time did I 

 rate the seeing above 3 on my scale. However, a comparison of his 

 standards of excellence and mine was interesting and useful. 



I took with me to Flagstaff the helioscope loaned to the expedi- 

 tion by the Yerkes Obser\'ator>^ Mr. Lowell very kindlj^ had it 

 fitted to the 24-inch telescope, therebj- making direct observations of 

 the sun possible. A number of very large sun spots were visible, 

 and much detail in them could be seen at times, but the moments of 

 steady images were of short duration. For the most part heat waves 

 followed each other rapidly, causing much movement of the image 

 and some blurring. 



When obser\'ations of the sun were made with the large telescope 

 the aperture was reduced by diaphragms placed in front of the 

 objective to 9, 12, or 18 inches. 



In addition to the direct observations, the sun's image was occa- 

 sionally projected upon a sheet of paper, usually to a scale of about 

 3 feet to the sun's diameter. Most of the obserx^ations of the sun 

 were made during the forenoon. The earliest ones were made about 

 7 a. m., and the^^ were usually continued at intervals until about 

 I p. m. On one of the days the sun was also obser^^ed about 5 p. m. 

 Observations of stars were made at night, after Mr. Lowell had 

 completed his work on Mars, usually until about midnight. On the 

 whole, the conditions during this portion of the night were much 

 better than those during the day. Double stars having equal com- 

 ponents and distances greater than o."25 were easily separated on 

 most of the nights, and the measurement of much closer pairs would 

 not have been difficult. Nevertheless, the seeing was not at any 

 time of the highest quality. The diffraction pattern of a star's 

 image was always more or less broken and in motion. 



During my stay at the Lowell Observ^atory I detected two double 

 stars, which appear to be new, and verified the duplicity of a third 

 which I had suspected with the 16-inch telescope of the Lowe Ob- 

 sen^atory. These pairs are as follows : 



