BULLETIN No. 357. 



SEPTEMBER, r9l8 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGIIICULTURAL EXPERIMENT 



STATION. 



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



Height of ha ro meter above ground, 51 ft. Above sea level, 2"/ 3.3 ft. 

 Height oj Wi?id Instruments y 2 ft. Time Jised, y^th Mer. 



MONTHLY SUMMARY. 



Pressnie. In inches. 

 Maximum reduced to freezing", 30. ,12 iith, 8 A 

 Minimum reduced to freezing, 29.40, 28th, 4 p 

 Reduced maximum reading . . 30.42, iitli, 8 A 

 Reducedt minimum reading, . 29.69, 28tfi, 4 p 



Mean semi-daily reduced 30.029 



Monthly range 0.73 



*Air Temperatore. In Degrees Fahr. 



Highest 84.0, 4th, 4 p 



Lowest 34-5. 3oth, 6 a 



Mean hourly 57.6 



Mean of means of max. and min 58.0 



Mean sensible (wet bulb) 53.2 



Monthly range 48 5 



Highest mean daily 71.6, 5th 



Lowest mean daily 47.8, 27th 



Mean maximum 69.1 



Mean minimum 46.9 



Mean daily range • 22.2 



Greatest daily range 38.0, 15th 



Least daily range 5.5,26th 



Humidity. 



Mean dew point 50.3 



Mean force of vapor 470 



Mean relative humidity 81.3 



Precipitaiion. In inches. 



Total precipitation, in inches 7.00 



Number of days on which .01 inch or more 



rain fell 15 



•Temperature in ground shelter. 

 ••Reduced to freezing and sea-level. 



Wind. 



Total movement 3271m 



Greatest daily movement 224m, 28th 



Least daily movement 30m, 15th 



Mean daily movement 109 m 



Mean hourly velocity 4.5 ni 



Maximum pressure per square foot, 4.5 lbs = 



30m per hour, 27th, 2 p, W. 

 Maximum velocity for 5 minutes, 24m per 



hour, 2Sth, 1:30 p, S. 

 Prevailing direction, West Southwest. 



Summary. 



South 13 per cent. 



South Southwest 20 " ■' 



West 17 " " 



North 10 " " 



-Southwest 10 " " 



North Northwest 13 " " 



Other directions 17 " " 



Weather. 



Mean cloudiness observed .... 56 per cent 

 Total cloudiness recorded by the Sun 



Thermometer . . 186 hours = 50 per cent 



Number of clear days 7 



Number of fair days 12 



Number of cloudy days 11 



Bright Sunshine. 



Number hours recorded, 187 hrs, = 50 per cent 

 Rain, ist, 6th, 7th, 8th, 9th, 12th, 13th, 

 17th, iSth, 20th, 2ist, 23d, 26th, 27th, 30th. 

 Thunder and Lightning, ist, iSth, 22d. 

 Frosts, nth, 22d, 30th. 

 Gales, 35 miles or more per hour : None. 



