BULLETIN No. 259. 



JULY, 1910 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGRICULTURAL EXPERIMENT 



STATION. 



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



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

 Height of Wind Instrutnents 72 ft. 



MONTHLY SUMMARY. 



Freaaure. In inclies. 



Maximuin reduced to freezing, 29 89, 12th, 7A.; 



19th, I?. P. 

 Minimum reduced to freezing. 29.32, 30th, 3 p. 

 Reduced] maximum reading, 30.18, i2tii, 7 A.; 



19th, 12 I'. 

 Reducedt minimum reading, . 29.61, 25th, 4 p.; 



30th, 3 P. 



Mean semi-daily reduced, 29.888 



Montiily range, 0.57 



*Air Temperature. In Degrees Falir. 



Higliest, 97.0. 24th, 3 p. 



Lowest, 48.5. 5th, 5 A. 



Mean iiourly, 72.1 



Mean of means of max. and min., .... 72.2 



Mean sensible (wet bulb), 64.8 



Monthly range 4S.5 



Highest mean daily, So.i.ioth 



Lowest mean daily, 64.0, 19th 



Mean maximum 85.2 



Mean minimum, 59-2 



Mean daily range, 26.0 



Greatest daily range, 36.0, 24th 



Least daily range, i7-o. 26th 



Uuttiidit!/. 



Mean dew point 61.0 



Mean force of vapor, 774 



Mean relative humidity, 70-3 



PreoipUation. In inches. 



Total precipitation, 1.90 



Number of days on which .01 inch or more 



rain felli ■ 



• Temperature in ground shelter, 

 t Reduced to freezing and sea-level. 



Wind. 



Total movement, 3812m. 



Greatest daily movement, .... 278m., 21st. 



Least daily movement 37m., ist. 



Mean daily movement 123m. 



Mean hourly velocity, 5.1m. 



Maximum pressure per square foot, 6.0 lbs.= 



35m. per hour, 4th, ip., N. N. E. 

 Maximum velocity for 5 minutes, 24ni. per 



hour 4th, IP., N.N.E. 

 Prevailing Direction, West Southwest. 

 Summary. 



Southwest . . 19 per cent 



South 16 " " ■ 



South Southwest 13 " " 



West 13 " " 



Northwest lo " 



Other directions 29 " " 



Weather. 



Mean cloudiness observed, . • • .34 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, 9ihrs.=20 per cent. 



Number of clear days, 17 



Number of fair days, 14 



Number of cloudy days, 



Bright Sunghine. 

 Number of hours recorded, . . 371 hrs.=8o^ 

 Rain, 7th, 8th, 12th, i6th, 19th, 22d, 25th, 26th. 

 27th, 2Sth, 30th. 



Gales, 35 or more miles per hour : 35 m, 4th, 

 N.N.E. 



Thunder and Lightning, 12th, i6th, 22d. 

 25th, 27th, 28th, 30th. 



