BULLETIN No. 355. 



JULY, 19 18 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGRICULTURAL EXPERIMENT 



STATION. 



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



Height of barometer above ground, 31 ft. Above sea level, 2yj.^ ft. 

 Height oj Wind Instruments y 2 ft. 7'itne used, y^th Mer. 



MONTHLY SUMMARY. 



Pressure. In inches. 

 Maximum reduced to freezing, 29. g3, 25th, 8 A 

 Minimum reduced to freezing, 29.40, 9th, i p 

 Reduced maximum reading . . 30.22, 25th, 8 

 Reducedt minimum reading, . 29.69, 9th, i p 



Mean semi-daily reduced 29.967 



Monthly range 0.53 



*Air Temperature. In Degrees Fahr 



Highest 99-5, 22d, 5 p. 



Lowest 45.0, 3d, 5 A. 



Mean hourly 70.1 



Mean of means of max. and min 71. i 



Mean sensible (wet bulb) ( 



Monthly range 54.5 



Highest mean daily 81.2, 23d 



Lowest mean daily 62.0, 2d 



Mean maximum 83.4 



Mean minimum 58.8 



Mean daily range 24.6 



Greatest daily range 38.5, 22d 



Least daily range 12.0, ist 



Humidity. 



Mean dew point 60.5 



Mean force of vapor 737 



Mean relative humidity 74.5 



Precipitation. In inches. 



Total precipitation, in inches 1.84 



Number of days on which .01 inch or more 



rain fell 6 



•Temperature in ground shelter. 

 ••Reduced to freezing and sea-level. 



Wind. 



Total movement 3093 m 



Greatest daily movement 240m, 30th 



Least daily movement i8m^ 19th 



Mean daily movement 100 m 



Mean hourly velocity 4.2 m 



Maximum pressure per square foot, 5.0 lbs = 



32m per hour, 29th, 6 P, S.S.W. 

 Maximum velocity for 5 minutes, 24m per 



hour, 29th, 6 p, S.S.W. 

 Prevailing direction. Southwest. 



Summary. 



South 16 per cent. 



North 16 " 



South Southwest 16 " 



Southwest ID " 



North Northeast 10 " 



Other directions 32 " 



Weather. 



Mean cloudiness observed .... 44 per cent 

 Total cloudiness recorded by the Sun 



Thermometer . . 176 hours = 38 per cent 



Number of clear days 7 



Number of fair days 19 



Number of cloudy days 5 



Bright Sunshine. 



Number hours recorded, 286 hrs, = 62 per cent 

 Rain, ist, 4th, 6th, 9th, loth, 13th, 17th, 



30th. 

 Thunder and Li^htnln^. lOth, 14th, 15th, 



17th, 30th. 

 Gales, 35 miles or more per hour :;None 



