62 



Academy of SciEisrcE. 



BAROMETER. 



Mean height of the barometer column, 29.102 inches. Mean, at 7 a. m., 29.126 

 inches; at 2 p.m., 29.077 inches; at 9 p.m., 29.103 inches: maximum, 29.856 inches, 

 at 7 a.m., January 9th; minimum, 28.344 inches, at 2 p.m., May 7th, giving a 

 yearly range of 1.512 inches. The highest monthly mean was in January, 29.803 

 inches; the lowest was in May, 29.006 inches. The barometer observations are cor- 

 rected for temperature, but not for elevation, thus affording the means of tleur- 

 mining the altitude of our station. 



RELATIVE HUMIDITY. 



Mean for the year, 65.53; at 7 a. m., 77.35; at 2 p. m., 46.58; at9 p. m., 73.68. 

 The dampest month was January; humidity, 78.10. The driest month was April; 

 humidity, 57.60. There were only five fogs during the year. The minimum humidity 

 for any single observation was 9 per cent, of saturation, at 2 p. m., March 27th. 



The following table gives the mean temperature, the extremes of temperature, the 

 relative humidity and the rainfall for each month of the year 1875, and a comparison 

 with preceding years: 



