186 



CARNEGIE INSTITUTION OF WASHINGTON. 



work will consist in the application of the results to physical problems among 

 the stars and in the laboratory. 



Somewhat similar in character to these researches is the list of the radial 

 velocities of 1,013 stars published by Adams and Joy. These values repre- 

 sent the product of the observations of several years and form a part of the 

 general program of the stellar spectroscopic department. The material 

 contained in this list has been utilized in a wide variety of investigations, 

 including those by Stromberg on space-motions, the relationship of absolute 

 magnitude to velocity, the study by Seares of the equipartition of energy, 

 and determinations of mean parallax from peculiar motion. The chief value 

 to astronomers of these results consists in the number of faint stars, mainly 

 of the dwarf class, concerning whose motions little has been known hitherto. 



OBSERVING CONDITIONS. 



The observing conditions at night during the year were nearly normal. 

 Although the precipitation was considerably below the average, the amount 

 of cloudiness varied but little from that of the mean for the past 11 years. 

 The precipitation for the year was 23.81 inches, as against an average value 

 for 19 years of 34.24 inches. The total snowfall was 49 inches. The mean 

 temperature for the year was 54.5°, the highest temperature 94° on June 29, 

 and the lowest 15° on February 1. The average wind velocity was 9.7 miles 

 an hour. 



The following table taken from the records for the 60-inch reflector shows 

 the distribution of observing weather with this instrument: 



During the year, 2,609 persons used the 60-inch telescope on public nights 

 and over 12,000 visited the museum and inspected the 100-inch reflector 

 during daylight hours. These data are taken from the meteorological and 

 other records maintained regularly by Hoge on Mount Wilson. 



