BULLETIN No. 345. 



SEPTEMBER, 19 17 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGRICULTURAL EXPERIMENT 



STATION. 



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



Height of barometer above ground, 5^ ft- Above sea level, 213.3 ft. 

 Height oj Wind histruments 72 ft. 



MONTHLY SUMMARY. 



Pressaie. In inches. 

 Maximum reduced to freezing, . 30.24, 23d. 8 A 

 Minimum reduced to freezing, . 29.^0, 30th, 4 p 

 Reduced maximum reading, . . 30.54, 23d, 8 A 

 Reducedt minimum reading, . 29.49, 30th, 4 P 



Mean semi-daily reduced 30.107 



Monthly range 1.05 



*Air Temperature. In Degrees Fahr. 



Highest 85.0, 19th, 3 p 



Lowest 30.5, nth, 6 A. 24th, 5 A 



Mean hourly 57-° 



Mean of means of max. and min 5S.4 



Mean sensible (wet bulb) S2 i 



Monthly range 54.5 



Highest mean daily 67.9, 2d 



Lowest mean daily 45.9,11th 



Mean maximum 72 



Mean minimum 44.0 



Mean daily range 28 



Greatest daily range 41.0, 19th 



Least daily range 6.5,1st 



Humidity. 



Mean dew point 49.7 



Mean force of vapor 436 



Mean relative humidity §3.5 



Precipitation. In inches. 



Total precipitation, in inches 2.42 



Total snow, in inces 



Number of days on which .01 inch or more 



rain fell 5 



Days of sleighing, . . . 



•Temperature in ground shelter. 

 •* Reduced to freezing and sea-level. 



Wind. 



Total movement 1702 m 



Greatest daily movement 179m, loth 



Least daily movement im, 26th 



Mean daily movement 57.0 m 



Mean hourly velocity 2.4 m 



Maximum pressure per square foot, 3.5 lbs = 



26 m per hour, 6th, 7 a, N. 

 Maximum velocity for 5 minutes i6m per 



hour, 6th, 7 A, N. 

 Prevailing direction, East. 



Summary. 



East 20 per cent 



Southwest 13 " " 



Northeast 10 " " 



North 10 " " 



Other directions 47 " " 



Weather. 



Mean cloudiness observed .... 39 per cent 

 Total cloudiness recorded by the Sun 



Thermometer . . 133 hours = 36 per cent 



Number of clear days 13 



Number of fair days u 



Number of cloudy days b 



Bright Sunshine. 



Number hours recorded, 240 hrs, = 64 per cent. 



Rain, ist, 2d Sth, 20th, 21st, 28th, 30th. 

 Thunder and Liiihtninti, ist, 2d, 20th, 30th 

 Frosts, nth, 12th, 23d, 24th. 

 Gales, 35 or more miles per hour. None. 



