BULLETIN No. 293. 



MAY, 1913 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGRICULTURAL EXPERIMENT 



STATION. 



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



Height of barometer above ground, S^ fi- Above sea level, 2^3.5 ft. 

 Height of Wind Instruments 72 ft. 



MONTHLY SUMMARY. 



Pressure. In inches. 



Maximum reduced to freezing, 30 10, 4th, 12P. 

 Minimum reduced to freezing, 29.23, 29th, 2P. 

 Reducedt maximum reading, 30.39, 4th, 12 p. 

 Reducedt minimum reading, 29.52, 29th, 2 p. 



Mean semi-daily reduced, 29.995 



Monthly range 0.87 



*Air Temperature. In Degrees Fahr. 



Highest, 89.0, 3d, 4 p. 



Lowest, 30.5,11th, 2:30 A. 



Mean hourly, 55.6 



Mean of means of max. and min 55.5 



Mean sensible (wet bulb), 5^4 



Monthly range, 5S.5 



Highest mean daily 73-2, 3d 



Lowest mean daily, 41-3. loth 



Mean maximum, 66.6 



Mean minimum, 44-3 



Mean daily range, 22.3 



Greatest daily range, 43-;. 2d 



Least daily range, 4-5. 28th 



Humidity. 



Mean dew point, 46.0 



Mean force of vapor, 445 



Mean relative humidity, ....... .73° 



Precipitation. In inches. 



Total precipitation, 4-94 



Number of days on wliich .01 inch or more 



rain fell, "13 



♦Temperature in ground shelter. 

 Reduced to freezing and sea-level. 



Wind. 



Total movement, 3672m. 



Greatest daily movement, .... 2S9m., 19th 



Least daily movement, 14m., 22d 



Mean daily movement 118 m 



Mean hourly velocity, 4-9 ni 



Maximum pressure per square foot, 5.5 lbs.= 



33m. per hour, 29th, 1 p., N.W. 

 Maximum velocity for 5 minutes, 30 m. per 



hour, 29th, 5P., N.W. 

 Prevailing Direction, Northwest. 



Summary. 



North Northwest 19 per cent. 



Northwest 16 " " 



West Northwest 13 " " 



South Southeast 13 " " 



Other directions 39 " " 



Weather. 



Mean cloudiness observed, . ■ ■ • 53 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, 232hrs. = 5i percent. 



Number of clear days 6 



Number of fair days, 14 



Number of cloudy days, n 



Bright Sunshine. 



Number of hours recorded, . . 221 hrs=49?S. 

 Rain, 6th, 9th, 13th, 15th, i6th, i8th, 21st, 

 22d, 23d, 24th, 25th, 27th, 28th, 29th. 

 Frosts, nth, i2th, 15th. 

 Tliunder and Lifflitning, 6th, 15th. 

 Gales, 35 or more miles per hour : None. 



