METEOROLOGICAL OBSEHVATORY 



Hatch Experiment Station 



MASSACHUSETTS AGRICULTURAL COLLEGE 



Latitude, 42° 23' -48.0" N. Longitude, 72° 31' 10" W. 



Height of instruments above ground^ 51 ft. Above sea level, 260 ft. 



BULLETIN No. 34, 



OCTOBER, 1891 



MONTHLY SUMMARY. 



Pressure. In inches. 

 Actual maximum reading, . 30.37, 12th, 8 a. 

 Actual minimum reading, . 29.29, 5th, 1 p.m 



Mean reduced to sea level 30.038 



Monthly range, 1.08 



*Air Temperature. In Degrees Fahr. 



Highest 82 ; 89 



Lowest 27 ; 20 



Mean 49.9; 48.7 



Monthly Range, 55; 69 



Highest mean daily 68.6; 72 



Lowest mean daily, •. . . 37; 35 



Mean maximum, 57.1; 61.3 



Mean minimum 41.8; 36.2 



Mean daily range, 15.3; 25.] 



Greatest daily range, 26. ; 38. 



Least daily range, 5; 11.5 



Humidity. 



Mean dew point 40.6 



Mean force of vapor, 4063 



Mean relative humidity, 65.5 



Wind. 



Prevailing Directions. 



North 19 per cent. 



North North East 13 " 



South West, 13 " 



South 11 " ." 



Other directions 44 " " 



Total movement 4319 m. 



Greatest daily movement 420 m., 23d* 



Least daily movement, 11m., 4th. 



Mean daily movement, 139.3 m. 



Mean hourly velocity 5.8 m. 



Maximum pressure per square foot, 9^1b8.= 

 39 m. per hour, 22d, at 11 p.m. 



* Precipitation. In inches. 

 Total precipitation, 2.22; 2.94 



Weather. 



Mean cloudiness observed, ... 54 per cent. 



Number of clear days 7 



Number of fair days 14 



Number of cloudy days, 10 



Total cloudiness recorded by the Sun Ther- 

 mometer, . . . 193 hours or .56 per cent. 

 Number of days on which .01 inch or more 

 rain fell, 7 



Bright Sunshine. 



Number of Hours recorded 150 



Rain, 7th, 8th, 13th, 14th, 16th, 20th,22d,26th, 

 27th. 



First Frost, 10th. 



Thunder and Lightning, 20th. 



Rainbow, 20th. 



Mean Ozone, 33 per cent. 



Halos. 



Solar 12th. 



Lunar 12th. 



Coronae, 11th, 12th, 1.5th, 19th. 



*The first figures denote readings at top of tower, the second at base. 



