BULLETIN No. 285. 



SEPTEMBER, 1912 



Meteorolooical Observations 



AT THE 



MASSACHUSETTS 



AGllICULTURAL EXPERIMENT 



STATION. 



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



Height of barometer above ground, 51 ft. Above sea level, 2"/^.^ ft. 

 Height of Wind Ifistruments 72 ft. 



MONTHLY SUMMARY. 



Pressure. In inches. 



Maximum reduced to freezing, 30 07, 28th, 8 A. 

 Minimum reduced to freezing, 29.33, i6th, i A. 

 Reducedt maximum reading, 30.37, 2Sth, 8 A. 

 Reducedt minimum reading, 29.62, i6th, i A. 



Mean semi-daily reduced 30.066 



Montlily range 0.75 



*Air Teinpei'ature. In Degrees Fahr. 



Highest 86.0, nth, 12M. 



Lowest 35-0. 3oth, 6 A. 



Mean hourly, 61.2 



Mean of means of max. and min., .... 61.6 



Mean sensiljle (wet bulb), 564 



Monthly range, 510 



Highest mean daily 73-5. • 5th 



Lowest mean daily, 45-o, 2gth 



Mean maximum, 72-3 



Mean minimum 50.9 



Mean daily range 21.4 



Greatest daily range, 36.5,17th 



Least daily range, 7-5. 2d 



Humidity. 



Mean dew point, 54-3 



Mean force of vapor, 525 



Mean relative humidity, 84.0 



Precipitation. In inches. 



Total precipitation, 2.52 



Number of days on which .01 inch or more 

 rain fell, '14 



•Temperature in ground shelter. 

 t Reduced to freezing and sea-level. 



Wind. 



Total movement 2980m. 



Greatest daily movement, .... 258ni., 16th 



Least daily movement iSm., 29th 



Mean daily movement gg.o m 



Mean hourly velocity, 4.1 m 



Maximum pressure per square foot, 3.5 lbs.= 



26m. per hour, i6th, 5 a., N.N.E. 

 Maximum velocity for 5 minutes, 20 m. per 



hour, i8th, IP., SS.W. 

 Prevailing Direction, North Northwest. 



Summary. 



North Northwest 10 per cent 



Northwest 13 " " 



South Southwest lo " " 



North Northeast 10 " " 



Southwest ic " " 



Northeast 10 " " 



Other directions 37 " " 



Weather. 



Mean cloudiness observed 60 per cent. 



Total cloudiness recorded by the Sun Ther- 

 mometer, 2i7hrs.=58 per cent. 



Number of clear days, . 5 



Number of fair days, n 



Number of cloudy days, 14 



Briglit Sxinshine. 



Number of hours recorded. . . 156 hrs.=425t 



Rain, ist, 2d, 3d. 4th, 5th, 6th, 7th, 15th, i6th, 



iSth, 19th, 20th, 24th, 29th. 



Tliiinder and Lis'itnins. 6th, 20th. 



Light Frost, 2Sth, 29th, 30th. 



Gales, 35 or more miles per hour : None. 



