BULLETIN No. 249. 



SEPTEMBER, 1909 



Meteorological Observations 



AT THK 



MASSACHUSETTS 



AGKICULTURAL EXPERIMENT 



STATION. 



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



Height of barometer above ground, 5^ fl- Above sea level, 2yj.^ ft. 

 Height of Wind Instruments 72 ft. 



MONTHLY SUMMARY. 



Fresstire. In inches. 



Maximum reduced to freezing, 30 22. 19th, S A. 

 Minimum reduced to freezing, 29.43, 5th, 11 A. 

 Reduced^ maximum reading, 30.52, igth, 8 A. 

 Reducedt minimum reading, . 29.72, 5th, 11 a. 



Mean semi-daily reduced, 30.114 



Monthly range 0.80 



*Air Teinperntiire. In Ilegrees Fahr. 



Highest 83.0, 14th, 3 p; 23rd 1:30 p. 



Lowest 35.0, 29th, 6 A. 



Mean hourly, 60.5 



Mean of means of max. and min 60.7 



Mean sensible (wet bulb), 55.4 



Montlily range, 48.0 



Highest mean daily, 72.7,23rd 



Lowest mean daily, 52.0, 20th 



Mean maximum, 72-3 



Mean minimum, 49.2 



Mean daily range, 23.1 



Greatest daily range, . . . . 38.0, 3rd; 29th 

 Least daily range, 7-o, loth 



Hiitnidity. 



Mean dew point, 52.6 



Mean force of vapor, 496 



Mean relative humidity, 83.1 



Precipitation. In inches. 



Total precipitation, 4-99 



Number of days on which .01 inch or more 

 rain or melted snow fell, '14 



Wind. 



Total movement 4008m. 



Greatest daily movement, . . . .276m., 5th. 



Least daily movement, 35ni., 22d. 



Mean daily movement 134m. 



Mean hourly velocity, 5.6 m. 



Maximum pressure per square foot, 5.5 lbs.= 

 33m. per hour, 5th, 2 P., N.N.W. 



Maximum velocity for 5 minutes, 30m. per 

 hour 4th, i2.'3o p., S.W. 



Prevailing Direction, Northwest. 

 Summary. 



North Northeast 17 percent. 



North Northwest 13 " " 



Southwest 10 " " 



West Northwest 10 " " 



Other directions, So " " 



Weather. 



Mean cloudiness observed, .... 55 per cent. 



Total cloudiness recorded by the Sun Ther- 

 mometer, i82hrs.=49 per cent. 



Number of clear days, 9 



Number of fair days g 



Number of cloudy days, 12 



Bright Sttnshine. 



Number of hours recorded, . . 192 hrs. = 5i^ 



Kain, ist, 4th, 5th, loth, nth, 13th, 15th, 

 i6th ,17th, 22d, 23d, 24th, 25th, 26th, 27th, 28th. 



Thunder and Liightning, ist. 



Gales, 35 miles or more per honr ; none 



* Temperature in ground shelter. 

 t Reduced to freezing and sea-leveL 



