SOI.AR RESEARCH AT MOUNT WILSON, CALIFORNIA. 



167 



TEMPERATURE. 



From March 25 to April 15 the temperature was recorded on a 

 self- registering thermometer. After April 15 this record was supple- 

 mented by observations of maximum and minimum thermometers. 

 The results are given (in degrees Fahrenheit) in the following table. 

 As bearing upon certain classes of night observations, the range of 

 temperature between 8 p. m. and 4 a. m. is also included. 



Temperature. 



ATMOSPHERIC PRESSURE. 



No complete barometric record has been kept, since this did not 

 seem of special importance in connection with the work. Neverthe- 

 less, an aneroid barometer has been read twice daily since July 13. 

 The maximum and minimum readings recorded up to September i 

 differed by only 0.22 inch. 



