BULLETIN No. 273. 



SEPTEMBER, 1911 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGKICULTURAL EXPERIMENT 



STATION. 



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



Height of ha ro meter above ground, 51 fi- Above sea level, 2^3.5 ft. 

 Height of Wind Instruments 72 ft. 



MONTHLY SUMMARY. 



Pressure. In inches. 



Maxumun reduced to freezing, 30.12,23d, 8 a. 

 Mininuim reduced to freezing. 29.27, 12th, iiA. 

 Reduced! maximum reading, 30.41, 8th, 11 A.; 



23d, 8 A. 

 Reducedt minimum reading, 29.56, 12th, 11 A 



Mean semi-daily reduced, 30.060 



Montlily range, 0.S5 



*Air Temperature. In Degrees Fahr. 



Highest 84.0, 2d, 2 p 



Lowest, 29.0, 14th, 6 A 



Mean iiourly, 60.2 



Mean of means of max. and min., .... 60.4 



Mean sensible (wet bulb), 55-4 



Monthly range 55-o 



Higliest mean daily, 7i.4i 2d 



Lowest mean daily, 4i.0i 29th 



Mean maximum, 7i-4 



Mean minimum 49-3 



Mean daily range, 22.1 



Greatest daily range, 38.0, 14th 



Least daily range, 4-o. 9th 



Humidity. 



Mean dew point, 52-9 



Mean force of vapor, S" 



Mean relative humidity 82.4 



Precipitation. In inches. 



Total precipitation, 34' 



Number of days on which .01 inch or more 

 rain felU • n 



Wiml. 



Total movement, 3809m 



Greatest daily movement, .... 263 m., 6th 



Least daily movement, 31m., 9th 



Mean daily movement 127.0m 



Mean hourly velocity, 5-3m 



Maximum pressure per square foot, 5.0 lbs.= 



32ni. per hour, i6th, 8 p., N.N.E. 

 Maximum velocity for 5 minutes, 24m. per 



hour, 6th, 7A., S.S.W. 

 Prevailing Direction, Northwest. 



Summary. 



North Northwest 17 percent. 



West 17 " " 



South Southwest 13 " " 



South 10 " ■ " 



North 10 " " 



Northeast 10 " 



Other directioiK 23 " " 



Weather. 



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

 Total cloudiness recorded by the Sun Ther- 

 mometer, i8ohrs.=48 per cent. 



Number of clear days, 6 



Number of fair days, i5 



Number of cloudy days, 9 



Bright Sunshine. 



Number of hours recorded, . . 195 hrs. = 52* 



Rain, 6th, 8th, gth, nth, 12th, 15th, 21st, 



22d, 2Sth, 26th, 27th, 29th. 



Sleet, 29th. 



Frosts, 14th, 27th. 



Thunder and Liglitning, 9th, 25th. 



Gales, 35 or more miles per hour : None. 



Temperature in ground shelter. 

 t Reduced to freezing and sea-level. 



