Meteorological Observations. 



xv 



Abstract of the Results of the Hourly Meteorological Observations 



taken at the Surveyor GeneraVs Office, Calcutta, 



in the month of July, 1859. 



Monthly Rfsults. 



Mean height of the Barometer for the month, 



Max. height of the Barometer, occurred at 10 A. M. on the 12th, 



Min. height of the Barometer, occurred at 4 A. M. on the 27th, 



Extreme Range of the Barometer during the month, 



Mean of the Daily Max. Pressures, 



Ditto ditto Min. ditto, .. 

 Mean daily range of the Barometer during the month, 



Inches. 

 29.530 

 29.762 

 28.721 



1 .Oil 

 29.597 

 29.452 



0.145 



Mean Dry Bulb Thermometer for the month, 

 Max. Temperature occurred at 3 p. m. on the 18th, 

 Min. Temperature occurred at 9 P. M. on the 26th, 

 Extreme range of the Temperature during the month, 

 Mean of the daily Max. Temperatures, 



Ditto ditto Min. ditto. 

 Mean daily range of the Temperatures during the month, 



o 



85.4 

 94,8 

 77.8 

 17.0 

 91.2 

 81.4 

 9.8 



o 



Mean Wet Bulb Thermometer for the month, .. .. 81.4 



Mean Dry Bulb Thermometer above Mean Wet Bulb Thermometer, . . 4.0 



Computed Mean Dew Point for the month, . . . . 79.4 



Mean Dry Bulb Thermometer above computed Meaa Dew Point, . . 6.0 



Inches. 

 Mean Elastic force of vapour for the month, .. „. .. 0.983 



Troy grains. 

 Mean weight of vapour for the month, . . . . . . 10.49 



Additional weight of vapour required for complete saturation, . . 2.19 



Mean degree of humidity for the month, complete saturation being unity, 0.83 



In dies. 

 Rained 1 5 days. — Max. fall of rain during 24 hours, . . . . 4.04 



Total amount of rain during the month, . . . . . . 9.09 



Prevailing direction of the Wind, . . . . . . . S. & S. E. 



On the 26th July, a high Northerly wind sprung up about 10 A. M. and con- 

 tinued to blow till 5 p. M. ; after which, a North Easterly wind set in, and blew for 

 about 3 hours. About 8 p. M. the wind veered and became Easterly, which rose 

 to a gale ; the directions of which during several hours of its continuance, were 

 as follows : 



From 8 p. m. till Midnight, Easterly. 



From Midnight till 1 a. m. on the 27th July,. Northerly. 



Erom. 1 a. M. till 8 a. m North Easterly. 



At 8 a. M. the gale ceased. 



During the prevalence of the gale there was incessant rain, but no thunder and 

 lightning. 



The Ten Minutes' observations taken during the gale, show that at 8 P. M. 

 which was the commencement of the gale ; the Barometer stood at 29.069 inches, 

 it then continuously descended till it became 28.719 inches at 3. h. 40 m. a. m. After 

 which, the Barometer began to ascend attaining to the height of 28.870 inches 

 at 7 a. M. The Ten Minutes' observations were given up at Ihis hour; but the 

 Barometer was observed to rise continuously (without indicating the usual tides) 

 till the Midnight of the 28th at which time, the height it stood at, was 29.453 

 inches. 



