BULLETIN No. 22 1. 



MAY, 1907. 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGRICULTURAL EXPERIMENT 



STATION. 



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



Height of barometer above ground, ^i ft. Above sea level, 2^3.5 ft. 

 Height of Wind Instrutnents 72 ft. 



MONTHLY SUMMARY. 



i^vessure. In inches. 



Maximum reduced to freezing, 30.04, 2d, gA. 

 Minimimi reduced to freezing, 29.37, 27th, 5 p. 

 Reducedl maximum reading, -30.34, 2d, 9 a. 

 Reduced! minimum reading, . 29.67, 27tli 5 p_ 



Mean semi-daily reduced, 29.996 



Montlily range 0.67 



* Air Temperature. In Degrees Fahr. 



Highest, 90.0, 14th, 2 p. 



Lowest, 25.0, 12th, 4:30 A. 



Mean hourly, S'-S 



Mean of means of max. and min., .... 51.7 



Mean sensible (wet bulb), 46.8 



Monthly range 65.0 



Highest mean daily 66.1,19th 



Lowest mean daily, 40.2, 4th 



Mean maximum, 62.6 



Mean minimum, 40.8 



Mean daily range, . ' 21.6 



Greatest daily range, 43-°, i4t'i 



Least daily range, 7.5,26th, 27tli 



HmnidUi/. 



Mean dew point, 42.2 



Mean force of vapor, 379 



Mean relative humidity, 75.3 



Freclpitation. In inches. 



Total precipitation, 4.02 



Number of days on which .01 inch or more 



rain or melted snow fell 11 



Total snow in inches trace 



* Temperature in ground shelter, 

 t Reduced to freezing and sea- level. 



Wind. 



Total movement, 5946 m. 



Greatest daily movement, .... 400 ni., 13th 



Least daily movement, 82m., 8th, 9th 



Mean daily movement 191 m. 



Mean hourly velocity, 7-9 ni. 



Maximum pressure per square foot, 6.5 lbs.= 

 36 ni. per hour, 4th, 5 p., W.N.W. 



Maximum velocity for 5 minutes, 24 m. per 

 hour loth, 2 p., W. 



Prevailing Direction, West Southwest. 



Summary. 



South, 16 per cent. 



North northwest, 13 " " 



Southwest, 10 " " 



West northwest, 13 " " 



West southwest 13 " " 



Other directions, 35 " " 



Weather. 



Mean cloudiness observed, . . . .68 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, 244hrs.=54 per cent. 



Number of clear days, 2 



Number of fair days, 17 



Number of cloudy days, 12 



Hright S^mshitie. 



Number of hours recorded, . . 209 hrs.=46^ 

 Krtm, 4th, 6th, 7th, Sth, 9th, nth, i6th, 17th, 



19th, 22d, 24th, 26th, 27th, 29th, 31st. 

 Snow, iitii. 

 Frosts, 5th, 22d. 

 Oales, 35 miles or more per hour, 36 m. 4th, 



W.N.W. 

 Thunder and Lightning , 16th. 



