BULLETIN No. 276. 



DECEMBER, 191 I 



Meteorological Observations 



AT THK 



MASSACHUSETTS 



AGRICULTUML EXPERIMENT 



STATION. 



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



Height of barometer above ground, 31 ft. Above sea level, 2yj.^ ft. 

 Height of Wind Instnwie/its 72 ft. 



MONTHLY SUMMARY. 



Pressure. In inches. 



Maxinimn reduced to freezing, 30 25,20th, 10 a. 

 Minimum reduced to freezing, 29.06, 27th, 5 p. 

 Reducedf maximum reading, 30.57, 20th, 10 A. 

 Keducedt minimum reading, 29.37, 27th, 5 p. 



Mean semi-daily reduced, 30-i53 



Monthly range, • - • i.2c 



*Air Temperature. In Degrees Fahr. 



Higliest 62.0, 12th, 3:30 p. 



Lowest lo.o, 5th, 7 A. 



Mean hourly, 32-7 



Mean of means of max. and min., .... 33.5 



Mean sensible (wet bulb), 28. g 



Monthly range, 52-0 



Highest mean daily, 53-7. 12th 



Lowest mean daily, 20.5, 5th 



Mean maximum, 40.9 



Mean minimum 26.1 



Mean daily range, U-S 



Greatest daily range, 33-°- 7th 



Least daily range 2.5, 15th 



Huniiflity. 



.Mean dew point, 23.9 



Mean force of vapor, .• • • -'^5 



Mean relative humidity 77-3 



Precipitation. 



Total precipitation. 



In inches. 



4.42 



Number of days on which .01 inch or more 



ram fell • 9 



Total snow in inches 4-5 



Snow on ground at end of month, 3 m 



Temperature in ground shelter. 

 t Keduced to freezing and sea-level. 



Wind. 



Total movement, 4857m 



Greatest daily movement, .... 6o2ni. ,28th 



Least daily movement, iSm., 8th 



Mean daily movement 157.0 m 



Mean hourly velocity, 6.5 m 



Maximum pressure per square foot, 30.5 lbs.= 



79m. per hour, 28th, 10:30 A., W.N. W. 

 Maximum velocity for 5 minutes, 40m. per 



hour, 28th, 2P., N.W. 

 Prevailing Direction. Northwest. 



Summary. 



Northwest 19 per cent. 



North 26 " " 



West 10 " " 



Other directions 45 " " 



Weather. 



Mean cloudiness observed, .... 63 per cent. 

 Total cloudiness recorded by the Sun Ther- 



mometer, . ... I78hrs.=63 per cent. 



Number of clear days, 6 



Number of fair days, 6 



Number of cloudy days, 19 



Bright Sunshine. 



Number of hours recorded, . . 119 hrs.=37^ 



Rain, 9th, 15th, l6th, 17th, 2 d, 23d, 26th, 27th, 



31st. 



Snow, isth, iSth, 31st. 



Days Sleighing, 1. 



Gales, 35 or more miles per hour : 35 m, 4th, 



N.: 43 m, 23d, W.N.W.: 79m, 2Sth, W.N.W.; 



45 m, 29th, N.W. 



