BULLETIN No. 3 13. 



JANUARY, 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. 



Pressure. In inches. 



Maxiniuni reduced to freezing, 30 24. 24th, loA. 

 Miiiiinmn leduced to freezing. 29.00, 19th, 6 a. 

 Reducedt nia.Kiniuni reading, 30.56, 24th, 10 A. 

 Reduced f niinimuni reading, 29.30, 19th, 6 A. 



Mean semi-daily reduced 3o-'23 



Montiily range, 1-26 



*Air Temperature. In Degrees Fahr. 



Higliest 540. 7th, 1:30 P. 



Lowest, -4.0, 5tli, S A 



Mean liourly, 26.2 



Mean of means of max. and min 27.1 



Mean sensible (wet bulb), 24.5 



Monthly range SS.c 



Highest mean daily, 45-4- 7th 



Lowest mean daily, 7-8. 3oth 



Mean maximum 35-2 



Mean minimum 19.0 



Mean daily range, 16.2 



Greatest daily range, 4i-0i 5th 



f.east daily range, 7-0- 24th 



Humidity. 



Mean dew point, 19 



Mean force of vapor, 147 



Mean relative humidity, So.S 



Precipitation. In inches. 



Total precipitation, 6 



Number of days on which .01 inch or more 



rain fell 



Total snow in inches ii-S 



*Temperature in ground shelter. 

 i Reduced to freezing and sea-level. 



Wind. 



Total movement, 39S6m. 



Greatest daily movement, .... 49oni., 13th 



Least daily movement, xm., 4th 



Mean daily movement 129 m 



Mean hourly velocity, 5-3 "^ 



Maximum pressure per square foot, 12.5 lbs.= 



5oni. per hour, 13th, 7 A., N. 

 Maximum velocity for s minutes, 30m. per 



hour. 7th, 6a., S.S-W.; 13th, 6A., N.; 19th, 



6a., S.S.W. 

 Prevailing Direction, West Northwest. 



Summary. 



West 19 per cent. 



North 16 " " 



North Northwest 16 " " 



Northwest 13 " " 



South ID " 



Other directions 26 " 



Weather. 



Mean cloudiness observed, . . .> 51 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, . . . i5ohrs.= 5i percent. 



Number of clear days 11 



Number of fair days, 9 



Number of cloudy days, 11 



Bright Sunshine. 



Number of hours recorded, . . 144 hrs = 49*. 



Rain, 6th, 7th, 12th, 13th, 17th, iSth,i9th, 23d, 



2-;th, 31st. 



Snow, 2d. 12th, 13th, 17th, 20th, 23d, 24th, 25th, 



27th, 28th, 31st. 



Hail, 17th. 



Days of Sleighing:, 13. 



Gales, 35 or more miles per hour : 49m, 7th, 

 S.S W ; 43m, i2th, N.; 50m, 13th, N.; 43m, 

 19th, S.S.W.; 36m, 24th, W. N. W. 



