BULLETIN No. 312. 



DECEMBER, 1914 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGRICULTURAL EXPERIMENT 



STATION. 



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



Height of barometer above ground, 31 ft. Above sea level, 2YJ.3 ft. 

 Height oj Wind Instruments 72 ft. 



MONTHLY SUMMARY. 



Pressure. In inches. 



Maxuuuni reduced to freezing, 30 36, 26th, up. 

 Miniiniim reduced to freezing, 28. 86, 14th, 5 A. 

 Keducedt maximum reading, 30.69, 26th, 11 p. 

 Reducedf minimum reading, 29.17, 14th, 5 A. 



Mean semi-daily reduced, 3o-'77 



Monthly range 1.52 



*Air Temperature. In Degrees Fahr. 



Highest 5S.5. 3d. 2 p 



Lowest -1S.5, 27th, 6 A 



Mean hourly, 24.2 



Mean of means of max. and min., .... 24.7 



Mean sensible (wet bulb), 207 



Monthly range 77-o 



Higliest mean daily, 47-5. 3d 



Lowest mean daily, -6.0, 27th 



Mean maximum, 33-2 



Mean minimum, 16.2 



Mean daily range, 17.0 



Greatest daily range, 3c.5. 28th 



Least daily range, 3-5. 9th 



Humidity. 



Mean dew point, i4-5 



Mean force of vapor, 140 



Mean relative humidity, 73-2 



Precipitation. In inches. 



Total precipitation 2.89 



Number of days on which .01 inch or more 



rain fell 8 



Total snow in inches 5.5 



* Temperature in ground shelter. 

 \ Keduced to freezing and sea-level. 



Wind. 



Total movement 4705m. 



Greatest daily movement, .... 42Sni., 22d 



Least daily movement im., 28th 



Mean daily movement, 152 in 



Mean hourly velocity 6.3 m 



Maximum pressure per square foot, 12.0 lbs.= 



49m. per hour, 21st, 8 P., W.N.W. 

 Maximum velocity for 5 minutes, 36m. per 



hour, 30th, 5 p., N.W. 

 Prevaihng Direction, West Northwest. 



Summary. 



North Northeast 26 per cent. 



West 16 " " 



North 10 " " 



West Southwest 10 " " 



North Northwest 10 " " 



Other directions 28 " " 



Weather. 



Mean cloudiness observed, .... 54 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, I23hrs. = 43 per cent. 



Number of clear days 11 



Number of fair days, 10 



Number of cloudy days, 10 



Bright Sunshine. 



Number of hours recorded. . . 160 lirs = 57*. 



Rain, 7th, 8th, 13th, 14th, 19th, 20th, 29th. 



Snow, 7th, loth, 13th, 14th, 19th, 20th, 22d,23d, 



24th, 27th. 



Days of Sleighing, 1 1. 



Gales, 35 or more miles per hour: 38m, 7th, 

 N.N E.; 45m, 14th, W.N.W.; 38111, 15th, 

 W.S.W.; 30m, 20th, N.W.; 49m, 21st, 

 W.N.W.; 42m, 22d, N.W.; 45m, -^oth, 

 N.W. 



