METEOROLOGICAL OBSEHVATORY 



Hatch Experiment Station, 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



Latitiulo, 12° 23' 4S.5" N. Longitiulo, 72° 31' 10" W. 



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



BULLETIN No 32. 



AUGUST, 1891 



MONTHLY SUMMARY. 



Pressure, In inches. 

 Actual in;ixiniuni reailing:, . 29.09, 2Gtli, 7 A. 

 Actual minimum reading;, . . 29.3S, 21st, 5 r. 



Mean reiluceil to sea level, 20.!»(;.5 



Monthly rauge C>1 



*Air Temperature. In Degrees Fahr. 



Highest 89; 92.5 



Lowest, .53 ; 4.5. 



Mean, 70.2; 09. 



Monthly Range, 36 ; 47..5. 



Highest mean daily, 78.4; 77.3 



Lowest mean daily, GI.5; 58.3 



Mean maximum, 78. ; 80.4 



Mean minimum, 02.4 ; .57.7 



Mean daily range, 15.6; 22.7 



Greatest daily range, 24. ; 34.5 



Least daily range, 3; 10.5 



Humidity . 



Mean dew point, 02.4 



Mean force of vapor 841 



]SIean relative humidity, 70.3 



Wind. 



Prevailing Directions. 



North 23 per cent. 



South, 14 " 



South West, 14 " 



South South West 11 " 



Other <lircctions 38 " " 



Total movement 3324 m. 



Greatest daily movement, .... 292 m., 21st 



Least daily movement, 32m., 9th 



Mean daily movement, 107.2 m. 



Mean hourly velocity, 4.5 m. 



Maximum pressure per .square foot, 2ilbs.^ 

 22 ra. per hour, 13th, at 11 A. anil^24 at 7 P. 



* Precipitation. In inches. 



Total precipitation, 3.43; 4.18 



Weather. 



Mean cloudiness observed, . . .58 per cent. 



Number of clear days, 10 



Number of cloudv days, 12 



Number of fair days, 9 



Total cloudiness recorded by the Sun Ther- 

 mometer, 226 hours or 52 per cent. 

 Number of days on which .01 inch or more 

 rain fell, H 



Briffht Hitnshine, 



Numl)cr of Hours recorded, . . . 

 Rain, 1st, 2d, 4th, 5th, 0th, 7th 



1.5th, 18th. 21st, 22(1, 23(1, 24th 



28th, 30th, 31st. 

 Thunder and Ijightnintj, 7th, 



2.3d, 28tli. 

 Mean Osonc, 2 



Halo.t. 

 Solar, 1st, 7th, 



0th, 

 20th, 



12th, 

 IG per 



. 204 

 12th, 

 27th, 



18th, 



cent. 



Ltinar coi'onae, 



2Gth, 

 14th, 



29th. 

 16th. 



*Tlie llrst (ijcurcs denote readings at top of tower, the second at base. 



