BULLETIN No. 324. 



DECEMBER, 1915 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGRICULTURAL EXPERIMENT 



STATION. 



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



Height of barometer above ground, 51 ft. Above sea level, 2yj.^ ft. 

 Height oj Wind Instruments 72 ft. 



MONTHLY SUMMARY. 



Pressnie. In inches. 

 Maximum reduced to freezing, 30.19, 3rst, 12 P 

 Minimum reduced to freezing, 28.55, 26tii, 9 A 

 Reduced! maximum reading, 30.52, 31st, 12 p 

 Reducedt minimum reading, 28. 85, 26th, 9 A 



Mean semi-daily reduced 29.949 



Montiily range 1.67 



*Air Temperatnre. In Degrees Fahr. 



Higliest 53.0, 26th, 4:30 A 



Lowest 2.0, 31st, 7 A 



Mean hourly 26.6 



Mean of means of max. and min 27.0 



Mean sensible (wet bulb) 23.3 



Monthly range 51.0 



Highest mean daily 36.5, iSth 



Lowest mean daily 16.3, 31st 



Mean maximum 34.5 



Mean minimum 19.4 



Mean daily range 15. i 



Greatest daily range 30.0, 26th 



Least daily range 6,0, 29th 



Hamidity. 



Mean dew point 17.9 



Mean force of vapor 162 



Mean relative humidity 



71.6 



Precipitation. In inches. 



Total precipitation 5. 86 



Number of days on which .01 inch or more 



rain fell 12 



Total snow in inches T2.3 



* Temperature in ground shelter. 

 t Reduced to freezing and sea-level. 



Wind. 



Total movement 4947 m 



Greatest daily movement 49om, 4th 



Least daily movement iim, 31st 



Mean daily movement 160 m 



Mean hourly velocity 6.7 m 



Maximum pressure per square foot, 13.0 lbs = 



Si m per hour, 26th, 2 .\, S. 

 Maximum velocity for 5 minutes, 48m per 



hour, 26th, 2 A, S. 

 Prevailing direction. West Northwest. 



Summary. 



Northwest 26 per cent 



West Northwest 16 " " 



South Southwest '3 " " 



North 10 " " 



South 10 " " 



West Southwest 10 " " 



North Northwest 10 •' " 



Other directions 5 " " 



Weather. 



Mean cloudiness observed .... 55 per cent 

 Total cloudiness recorded by the Sun 



Thermometer . . 177 hours = 62 per cent 



Number of clear days 9 



Number of fair days 6 



Number of cloudy days 16 



Bright Sunshine. 



Number hours recorded, 106 hrs, = 38 per cent. 

 Rain. 2d, 8th, 9th, 13th, 14th, 17th, i8th, 23d, 



25th, 26th, 28th, 29th. 

 Hail, 17th, 29th. 

 Snow. 2d. 6th, Sth, 9th, 13th, 14th, 19th, 20th, 



26th, 2Sth, 29th. 

 Gales, 35 or more miles per hour: 40m, loth, 



N.W.: 49ni, 13th, IV.N.W.; 49m, 14th, 



N.N.W,; 37m, 15th, W.. 37m, i8th, N.W.; 



5tm, 26th, S. 



