BULLETIN No. 257. 



MAY, 19 10 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGRICULTURAL EXPERIMENT 



STATION. 



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



fleight of barometer above ground, ^i ft. Above sea level, 2yj.^ ft. 

 Height of Wind Instruments y2 ft. 



MONTHLY SUMMARY. 



Fressure. In inches. 



M;i.Kiimun reduced to freezing, 30 10, i6th, S A. 

 Miniinum reduced to freezing, 29.09, 31st, 4 p. 

 Reduced! niaxinniin reading, 30.40, i6tli, 8 A. 

 lieducedt minimum reading, . 29.38, 31st, 4 p. 



Mean semi-daily reduced, 29.962 



Monthly range 1.02 



*Air Temperature. In Degrees Fahr. 



Highest, S4.0, 24th, 4 p. 



Lowest 31-0. 6th, 5 A. 



Mean hourly, 56.1 



Mean of means of max. and min 57.0 



Mean sensible (wet bulb), 50.2 



Monthly range 53-° 



Highest mean daily 69.9,24th 



Lowest mean daily, 45-2, 5th 



Mean maximum, 67.7 



Mean minimum, 46.3 



Mean daily range 21.4 



Greatest daily range, 37-o. 20th 



Least daily range, 7.0, 9th 



Humidity. 



Mean dew point, 45-5 



Mean force of vapor, 443 



Mean relative humidity, 71.6 



freoipitation. In inches. 



Total precipitation, 2.67 



Number of days on which .01 inch or more 

 rain or melted snow fell -16 



Wind. 



Total movement 5289111. 



Greatest daily movement, .... 3i3ni., 4th. 



Least daily movement 74m., i6th. 



Mean daily movement I7ini. 



Mean hourly velocity, 7.1 m. 



Maximum pressure per square foot, 7.5 lbs.= 



39m. per hour, 7th, 3 p., W.N.W. 

 Maximum velocity for 5 minutes, 30m. per 



hour 28th, 5P., N. 

 Prevailing Direction, West. 

 Summary. 



West Northwest 29 per cent. 



South Southwest 13 " " 



Southwest 13 " " 



North Northwest 10 " " 



Other directions, 35 " " 



Weather. 



Mean cloudiness observed, . . . .66 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, i66hrs.=37 per cent. 



Number of clear days, 13 



Number of fair days, 14 



Number of cloudy days, 4 



Briff/it Sunshine. 

 Number of hours recorded, . . 2S7 lirs.=63^ 

 Rain, ist, 2d, 3d, 4th, 5th, 8th, 9th, loth, 13th, 

 14th, i8th, 2ist, 23d, 24th, 25th, 26th, 27th, 30th, 

 31st. 



Frost, 6th. 



Gales, 35 miles or more per hour ; 39m, 

 3d,S.S.E.;37m,4th,N.N.W.; 39m, 7th,W.N.VV.; 

 37m, 2Sth, N. 



Thunder and Lightning:, ist, 2d, 3d, 14th, 

 18th. 



* Temperature in ground shelter. 

 t Reduced to freezing and sea-level. 



