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, 273-5 fi- 

 Height of Witid Instruments 72 ft. 



APRIL, 1900. 



BULLETIN No. 136. 



MONTHLY SUMMARY. 



Preasure, In inches. 



Maximum reduced to freezing, 30.17, i6th, 7 A. 

 .Minimum reduced to freezing^, 29.17, 7tli, 4P. 

 Reducedt maximum reading, 30.48, 16th, 7 a. 

 Reducedt minimum reading, 29.47, 7th, 4 p- 



Mean tri-daily reduced 29.956 



Monthly range • i.oi 



*Air Temperature, In Degrees Fahr. 



Highest, 80.0,30th, 2:30?. 



Lowest 21.0, loth, 5:30 A. 



Mean hourly 46.9 



Mean of means of ma.\. and min., .... 45.8 



Mean sensible (wet bulb), 42.2 



Monthly range, 59.0 



Highest mean daily, 60.3, 19th 



Lowest mean daily, 32.5, gth 



Mean maximum, 57.7 



Mean minimum, 33.9 



Mean daily range, 23.8 



Greatest daily range, 44.5, 30th 



Least daily range, 8.0, 12th 



MutrtiAiUj. 



Mean dew point, 34.9 



Mean force of vapor 349 



Mean relative humidity, . . . • ... .64.7 



Precipitation. In inches. 



Total precipitation, . • 1.85 



Numlier of days on which .01 inch or more 



rain or melted snow fell, — 7 



Snow total in inches, Traces 



• Temperature in ground shelter. 

 t Reduced to freezing and sea-level. 



Wind. 



Total movement, 5039 m* 



Greatest daily movement, .... 372 m., 7th 



Least daily movement 30 m., 21st 



Mean daily movement 168.0 m. 



Mean hourly velocity 7.0 m. 



Maximum pressure per square foot, 13.0 lbs.= 



51 m. per hour, 26th, 3 p., N.N.E. 

 Prevailing Direction, North Northwest. 

 Summary. 



North, 23 per cent. 



Northwest, 10 " " 



North, Northwest, 10 " " 



North Northeast, 23 " " 



Southwest 10 " " 



Other directions, 24 " " 



Weatlier. 



.Mean cloudiness observed, .... 46 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, ..... 203 hrs.=47 per cent. 



Number of clear days, 9 



Number of fair days, 12 



Number of cloudy days, 9 



Bright Sunshine. 

 Number of hours recorded, . . . 227 hrs. = 53i( 

 Rain, 2d, 3d, 12th, 13th, 14th, 17th, iSth, 19th, 



22d, 23d, 30th. 



Snow, 9th. 



Thunder and Lightning, 30th. 



Gales, 35 miles or more per hour, 50m., ist, 

 W.N.W.; 36m., 2d, S.W.; 39m., 3d, 

 N.W.; 4Sm.. 6th, N.N.W.; 47m., 7th, 

 N.: 39m., 8th, N.N.W.; 39m., 14th, W.; 

 42m., 19th, W.N.W.; 37m., 24th, N.E.; 

 43m., 25th, N.E.; sun.. 26th, N.N.E.; 

 37m. ,127th, N.E.; 48m, 30th, S.W. 



