BULLETIN No. 288. 



DECEMBER. 1912 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGRICULTUIUL EXPERIMENT 



STATION. 



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



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

 Height of IVind Instruments 72 ft. 



MONTHLY SUMMARY. 



Pressure. In inches. 



Maxiuium reduced to freezing, 30 29, ist, lo A. 

 Minimuin reduced to freezing. 28. 84, 27th, 4 p. 

 Reducedt maximum reading, 30.61, 1st, 10 A. 

 Keducedt minimum reading, 29.15, 27th, 4 p. 



Mean semi-daily reduced, 30.009 



Monthly range, 1.46 



*X\r Temperature. In Degrees Fahr. 



Highest 65.0, 6th, 2:30 P. 



Lowest 3-0, 25th, 5 A. 



Mean hourly, 32-9 



Mean of means of max. and min 33.1 



Mean sensible (wet bulb), 28. 9 



Monthly range 62.0 



Higliest mean daily 49-i. 6th 



Lowest mean daily 20.5, gth 



Mean maximum, 40.8 



Mean minimum, 25.3 



Mean daily range iS-"! 



Greatest daily range, 37-o. 25th 



Least daily range, 4.0,20th 



Humidity. 



Mean dew point 23.5 



Mean force of vapor, 183 



Mean relative humidity, 75-4 



Precipitation. In inches. 



rotal precipitation 404 



Mumber of days on which .01 inch or more 



rain fell, • ' ° 



Total snow in inches 5° 



♦Temperature in ground shelter. 

 Reduced to freezing and sea-level. 



Wind. 



Total movement, 5337in. 



Greatest daily movement, .... 4iSn)., gth 



Least daily movement, iini., 5th 



Mean daily movement, 172 m 



Mean hourly velocity, 7.2 m 



Maximum pressure per square foot, lo.o Ibs.^ 



45m. per hour, 8th, 9 p., W.S.W. 

 Maximum velocity for 5 minutes, 36 m. per 



hour, 8th, 12 p.,W.S.W. 

 Prevailing Direction, West Southwest. 



Summary. 



South Southwest 16 per cent 



Northwest 13" 



West Southwest 13 " 



West 16 " " 



Southwest 13 *' " 



South 10 " " 



Other directions 19" 



Weather. 



Mean cloudiness observed 58 per cent. 



Total cloudiness recorded by the Sun Ther- 

 mometer, 13s hrs. =48 per cent. 



Number of clear days, 8 



Number of fair days, " 



Number of cloudy days, 12 



Bright Sunshine. 



Number of hours recorded, . . I48hrs. = 5* 



Rain. 2d, jth, 6th, 8th, 17th, i8th, 24th. 27th, 



30th. 



Sno-w, Sth, 13th, 24th, 27th. 



Days of Sleighing, 4. 



Gales, 35 or more miles per hour : 4; m, 8th^ 



W.S.W.; 36m , i2th, W.; 41m., 19th, W.S.W.; 



41m., 27th, W.N.W.; 38 m-, 28th, W.N.W.; 



'40 111.. 30th, S.W. 



>7 



