BULLETIN No. 388. 



APRIL. 192 1 



Meteorological Observations 



AT THK 



MASSACHUSETTS 



AGUICULTUIUL EXPElllMKNT 



STATION. 



Latitude, 42° 23' 48.5" N. Longitude 72* 31' 10" W. 



Height of barometer above grounti, ^i ft. Above sea level., 2jj.§ ft. 

 Height oj Wind Instruments J2 ft. Time used, y^ihAIer. 



MONTHLY SUMMARY. 



Pressnie. In inches. 

 Maximum rednced to freezing, 30.26, 7th, 12 m 

 Minimum reduced to freezing, 29.22, 30th, 10 v 

 Reduced maximum reading . 30.56, 7th, 12M 

 Reduced mininuim reading, 29.51, 30th, 10 p 



Mean semi-daily reduced 3o.o55 



Monthly range 1.05 



*Air Temperature. In Degrees Fahr. 



Highest S5.0, 6th, 4 P 



Lowest 25.5, 2d, 7 A 



Mean hourly 5i-5 



Mean of means of max. and min 52.0 



Mean sensible (wet bulb) 46.4 



Monthly range 59 



Highest mean daily 64.6. 5 th 



Lowest mean daily 36.5, nth 



Mean ma-ximum 63 



Mean minimum 40 2 



Mean daily range 23.6 



Greatest daily range 44.0, Dth 



Least daily range 6.0, 15th 



Hnmidity. 



Mean dew point 43.2 



Mean force of vapor 3S4 



Mean relative humidity 76.9 



Precipitation. In inches. 



Total precipitation, in inches 6.47 



Total snow, in inches 1.0 



Number of days on which .01 inch or more 



rain fell 13 



•Temperature in ground shelter. 

 ••Reduced to freezing and sea-level. 



Wind. 



Total movement 4S67 m 



Greatest daily movement 320m, 12th 



Least daily movement 43ni 8th 



Mean daily movement 162m 



Mean hourly velocity 6.7 m 



Maximum pressure per square f(K)t, 6.5 lbs = 



36m per hour, 3d/ i a, \V.; 15th, 10 A, S 

 Maximum velocity for 5 minutes, 24m per 



hour, iSth, 10 A, S. 

 Prevailing direction, North Northeast. 

 Summary. 



North 17 percent 



North Northeast 10 " " 



East 13 " " 



East Southeast 10 " " 



South Southwest 20 " " 



Southwest 10 " " 



Other directions 20 " " 



Weather. 



Mean cloudiness observed .... 62 per cent 

 Total cloudiness recorded by the Sun 



Thermometer . . 187 iiours = 46 per cent. 



Number of clear days 5 



Number of fair days 16 



Number of cloudy days 9 



Bright Sunshine. 



Number hours recorded, 215, = 53 per cent. 

 Rain, 1st, 7th. 8th, 9th, 15th, i6th, 17th, i8th, 



19th, 2ist, 22d, 23d, 24tll, 29th,30til. 

 SnoM", l8th. 

 Hail. 18th. 



Frosts after the 15th, none. 

 Gales. 36m. 3d, W.: 36m, i:;th, S. 



