BULLETIN No. 340. 



APRIL, 1917 



Meteorological Observations 



MASSACHUSETTS 



AGRICULTURAL EXPERIMENT 



STATION. 



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



Height of haroiiieter above ground, ^r ft Above sea level, 2yj.^ fi. 

 Height oj Wind Instruments y2 ft. 



MONTHLY SUMMARY. 



Pressuie. In inches. 

 Maximum reduced to freezing, 30.03, 17th, S a 

 Minimum reduced to freezing, 28. 93, 6th, 5 p 

 Reducedt maximum reading, 30.33, 17th, 8 A 

 Reducedt minimum reading, 29.24, 6th, 5 f 



Mean semi-daily reduced 29.925 



Monthly range 1.09 



*Air Temperature. In Degrees Fahr. 



Highest 71.0, 19th, 4 p 



Lowest 25.0, 15th, 6 A 



Mean hourly 42.9 



Mean of means of max. and min 42.1 



Mean sensible (wet bulb) 39.1 



Monthly range 46.0 



Highest mean daily 58.3, 22d 



Lowest mean daily 31.0,9th 



Mean maximum S3 



Mean minimum 34.2 



Mean daily range 18.8 



Greatest daily range 35.0, 25th 



Least daily range ■ . . . . 7.0, 30th 



Humidity. 



Mean dew point 34.3 



Mean force of vapor 279 



Mean relative humidity 74.6 



Precipitation. In inches. 



Total precipitation, in inches 1.83 



Total snow, in inches Trace 



Number of days on which .01 incli or more 



rain fell 10 



* Temperature in ground shelter. 

 t Reduced to freezing and sea-level. 



Wind. 



Total movement 3853 m 



Greatest daily movement 6iim, nth 



Least daily movement 14m, ist 



Mean daily movement 12S m 



Mean hourly velocity 5.3 m 



Maximum pressure per square foot, 35.0 lbs = 



84m per hour, loth, 3 p, N.W. 

 Maximum velocity for 5 minutes 40m per 



hour, loth, 3 p, N.W. 

 Prevailing direction, West Northwest. 



Summary. 



Northwest 33 per cent 



West Northwest 17 " " 



South 13 " " 



Other directions 37 " " 



Weather. 



Mean cloudiness observed .... 46 per cent 

 Total cloudiness recorded by the Sun 



Thermometer . . 108 hours = 27 per cent 



Number of clear days i6 



Number of fair days 10 



Number of cloudy days 4 



Bright Sunshine. 



Number hours recorded, 294 hrs, =: 73 per cent 

 Rain, ist, 6th, 7th, 12th, iSth, 20th, 21st, 26th, 



27th, 2qth, 30th. 

 Snow, I2th, 27th. 

 Thunder and Lightning, ^ist. 

 Gales, 35 or more miles per hour. 4oni, 4th, 



N.W.; 36m, 7th, N.W.; 39m., 9th, N.N.W.; 



84m, loth, N.W. 



