BULLETIN No. 28 1. 



MAY, 1912 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGRICULTUIIAL EXPERIMENT 



STATION. 



Latitude, 42° 23' 48,5" N. Longitude 72° 31' 10" W. 



Height of barometer above ground, 31 ft. Above sea level, ^73-5 fi- 

 Height of Wind Instruments 72 ft. 



MONTHLY SUMMARY. 



Pressure. In inches. 



Maxiiniun reduced to freezing, 3001,20th, 9 A. 

 Miniiniiin reduced to freezing, 29.15, 9th, 3 p. 

 Reducedl maximum reading, 30.31,20th, 9 A. 

 Keducedf minimum reading, 29.45, 9th, 3 p. 



Mean semi-daily reduced, 29.961 



Montlily range, 0.S6 



*Air Temperature. In Degrees Fahr. 



Highest, 88.0. 24th, I p 



Lowest 325. 1st, 6 A 



Mean hourly, 58.1 



Mean of means of max. and min., .... 58.S 



Mean sensible (wet bulb), 53 4 



Monthly range 55-5 



Higliest mean daily, 70.4,24th 



Lowest mean daily 47-0, 5th 



Mean maximum 69.7 



Mean minimum, 47-8 



Mean daily range, 21 



Greatest daily range, 4i-o, 21st 



Least daily range, 4-5' i6th 



Humidity. 



Mean dew point 50-2 



Mean force of vapor 482 



Mean relative humidity, 785 



Precipitation. In inches. 



Total precipitation, 4-34 



Number of days on which .01 inch or more 

 rain fell • "^ 



♦Temperature in ground shelter. 

 t Reduced to freezing and sea-level. 



Wind. 



Total movement, 5332m. 



Greatest daily movement, .... 371m., aSth 



Least daily movement, 78m., 30th 



Mean daily movement, 172 m 



Mean hourly velocity, 7.2 m 



Maximum pressure per square foot, 13.5 lbs.= 

 52m. per hour, 17th, i p., W.; 19th, 3 P., 

 - W. N. W. 

 Maximum velocity for 5 minutes, 42 m. per 



hour, 17th, I P., W. 

 Prevailing Direction, Southwest. 



Summary. 



South .Southwest 16 per cent. 



South [3 " " 



West 13 " " 



Other directions 5S " " 



Weather. 



Mean cloudiness observed, .... 64 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, 239 his. = 53 per cent. 



Number of clear days, 7 



Number of fair days, 12 



Number of cloudy days, 12 



Bright Sunshine. 



Number of hours recorded, . • 214 hrs. = 47* 

 Rain, 5th, 6th, 8th, 9th, 10th, 12th, 14th, 



15th, i6th, 17th, 20th, 2ist, 23d, 24th, 



29th, 30th, 31st. 

 Frost, ist. 

 Thunder and Lightning, 9th, 21st, 24th, 



30th. 

 Hail, 9th, 2ist. 

 Gales, 35 or more miles per hour : 44m, 14th, 



W.; 52m, 17th, W.; 52ni, 19th, W.N.W. 



