METEOROLOGICAL OBSERVATORY 



OF THE 



Hatch Experiment Station 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



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



Height of barometer above ground, 31 ft. Above sea level, 2^3.3 ft. 

 Height of Wind Instruments 72 ft. 



BULLETIN No- 160. 



APRIL, 1902. 



MONTHLY SUMMARY. 



Pressure. In inches. 

 Maximum reduced to freezing, 29.98, 25th, 7 a. 

 Minimum reduced to freezing, 2S.93. ist, 4 A. 

 Reducedt maximum reading, 30.28, 25th, 7 A. 

 Reducedt minimum reading, 29.24, ist, 4 a. 



Mean tri-daily reduced, 29.S76 



Monthly range, . . . . ■ 1.04 



*Air Temperature. In Degrees Fahr. 



Highest, 83.0, 22d, 3 p. 



Lowest, 25.5, 15th, 6 A. 



Mean hourly, 47-3 



Mean of means of max. and min., .... 47.2 



Mean sensible (wet bulb), 42.7 



Monthly range, ; 57-5 



Highest mean daily, 63.3, 22d 



Lowest mean daily, 38.3, ist 



Mean maximum, 57.9 



Mean minimum, 36.5 



Mean daily range 21.4 



Greatest daily range, 41.0,23d 



Least daily range, 7.0, 8th 



II II in id it I). 



Mean dew point, 36.3 



Mean force of vapor 353 



Mean relative humidity, 67.1 



Precipitation. In inches. 



Total precipitation, 3.31 



Number of days on wiiich .01 inch or more 



rain or melted snow fell, 13 



Smou>, total in inches, T. 



Wind. 



Total movement, 4642m. 



Greatest daily movement, 364m., 2d. 



Least daily movement, 24m., 4th. 



Mean daily movement 154.7 ni. 



Mean hourly velocity, 6.4 m. 



Maximum pressure per square foot, 14.0 lbs. = 



53 m. per hour, 27th, 11 a., N.W. 

 Prevailing Direction, Northwest. 

 Summary. 



North, 10 per cent. 



North, Northeast, 10 " " 



Southeast, 10 " " 



Southwest, 10 " " 



West Southwest, 13 " " 



West, 10 " " 



Other directions 37 " " 



Weather. 

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

 Total cloudiness recorded by the Sun Ther- 

 mometer, 263 hrs.=65 per cent. 



Number of clear days, -j 



Number of fair days, jo 



Number of cloudy days, 17 



Bright Sunskine. 



Number of hours recorded, . . . 139 hrs.=355< 



Main, ist, 6th, 7th, 8th, 9th, loth, nth, 12th, 



13th, iSth, 20th, 2ist. 23d, 25th, 26th, 27th, 



29th, 30th. . / . 



Snow, 2d 



Thunder and lAghtning, 26th, 30th. 



Oales, 35 miles or more per nour, 3;m., 



ist, N.N. W.: 37m.. 2d. N.N.W.; 45m., Sthi 



E.S.E.; 40m., 9th. S.E.: 3;ni., 23d, N. 



N.E.; 39m., 24th. N.N.E.: 53ni., 27th, N. 



W.; 36m., 29th, W.N.W. 



* Temperature in ground shelter, 

 t Reduced to freezing and sea-level. 



