BULLETIN No. 250. 



OCTOBER, 1909 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGRICULTURAL EXPERIMENT 



STATION. 



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



Height of barometer above ground, ^i ft. Above sea level, 2jj.^ ft. 

 Height of Wind Instruments 72 ft. 



MONTHLY SUMMARY. 



Pressure. In inches. 



Maxiniinn reduced to freezing, 30 21, 20th, 8 A. 

 Minimum reduced to freezing, 29.25, 15th, 2 p. 

 Reduced^ maximum reading, 30.52, 20th, 8 A. 

 Reduced! minimum reading, . 29.55, 15th, 2 p. 



Mean semi-daily reduced, 3°-°35 



Monthly range 0.97 



*Air Temperature. In Degrees Fahr. 



Highest, 85.0, loth, 3 P. 



Lowest,. 24.0, 2ist, 7 A. 



Mean hourly, 47.7 



Mean of means of max. and min., .... 48.7 



Mean sensible (wet bulb), 424 



Monthly range 61.0 



Highest mean daily 61.5, loth 



Lowest mean daily 33-8, 29th 



Mean maximum, 60.6 



Mean minimum, 36.7 



Mean daily range, 23-9 



Greatest daily range, 42.0, 7th 



Least daily range, 5.5,24th 



Huiniditi/. 



Mean dew point, 38.0 



Mean force of vapor, 3i7 



Mean relative humidity, 76.1 



Precipitation. In inches. 



Total precipitation, 1.23 



Number of days on which .01 inch or more 

 rain or melted snow fell, • 9 



Wind. 



Total movement, 440001. 



Greatest daily movement, . . . .343m., 29th. 



Least daily movement 26m., 8th. 



Mean daily movement 142m. 



Mean hourly velocity, 5-9 m. 



Maximum pressure per square foot, 8.5 lbs.= 



41m. per hour, 17th, 11 A., N.W. 

 Maximum velocity for 5 minutes, 27m. per 



hour 17th, 12 M., N.W. 

 Prevailing Direction, West Northwest. 

 Summary. 



North 13 per cent. 



North Northwest 10 " " 



Northwest 16 " " 



West Northwest 19 " " 



Other directions, 42 " " 



Weather. 

 Mean cloudiness observed, . . . .49 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, i47hrs.=43 per cent. 



Number of clear days, 10 



Number of fair days, 11 



Number of cloudy days, 10 



Bright Sunshine. 

 Number of hours recorded, . . 194 hrs. = 57?( 

 Rain, 3d, nth, 12th, 14th, 15th, i6th, 17th, 



i8th,2ist,23d, 24th, 2Sth. 

 Thunder and Lightning, 2i5t, 23d. 

 Frosts, 13th, 14th, i6th, 17th, i8th, 19th, 20th, 



2ist, 26th, 30th, 

 Gales, 35 miles or more per hour ; 41m. 



17th, N.W. 



* Temperatute in ground shelter. 

 t Reduced to freezing and sea-level. 



