METEOROLOGICAL OBSERVATORY 



Hatch Experiment Station, 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



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



Height of barometer above groiuui, ^i ft. Above sea level, 2JJ.^ ft. 

 Height of Wind Instruments y2 ft. 



MAY, 1899. 



BULLETIN No. 125. 



MONTHLY SUMMARY. 



Pressure. In inches. 

 Maximum reduced to freezing, 29.99, 24th, 7 A. 

 Minimum reduced to freezing, 29.41,9111, 2P. 

 Reducedt maximum reading, 30.29, 24tli, 7 a. 

 Reducedt minimum reading, . 29.69, 9th, 2 p- 



Mean tri-daily reduced, 30.000 



Montlily range, . . . . • 60 



*Air Teniperatitre. In Degrees Fahr. 



Highest, 88.5, ist, 3 p. 



Lowest, 33., 4th, 5 A. 



Mean hourly, 55.7 



Mean of means of max. and min., .... 57.6 



Mean sensible (wet bulb), 53.4 



Monthly range 55.5 



Highest mean daily 70.0,31st 



Lowest mean daily, 46.8, i6th 



Mean maximum, 71.2 



Mean minimum, 44.0 



Mean daily range, 27.2 



Greatest daily range, 40.0, 24th 



Least daily range, 6.5, 19th 



Humidity, 



Mean dew point, 4S.6 



Mean force of vapor, 534 



Mean relative humidity, . . . • ... .70.3 



Precipitation. In inches. 



Total precipitation, . • 1.28 



Number of days on which .01 inch or more 

 rain or melted snow fell, 9 



Wind. 



Total movement, 4219 ni. 



* Temperature in ground shelter, 

 t Reduced to freezing and sea-level. 



Greatest daily movement, ... 284 m., 27tli 



Least daily movement 48 m., i6th 



Mean daily movement, 136. m. 



Mean hourly velocity, 5.7 



Maximum pressure per square foot, 10.5 Ibs.^ 



46 m. per hour, on ist, 7.30 p., S. S. W. 

 Prevailing Direction, Southwest. 



Summary. 



Southwest, 26 per cent. 



South southwest, 13 " " 



Northeast, 13 " " 



North, 10 " " 



Other directions, 38 " " 



Weather. 



Mean cloudiness observed, .... 54 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, 232 hrs. =51 per cent. 



Numter of clear days, 7 



Number of fair days, 12 



Number of cloudy days, 12 



Bright Sunshine. 



Number of hours recorded, . . . 221 hrs.=495{ 



Rain, ist, 2d, nth, 13th, i6th, 17th, T8th, 19th, 

 2otli, 2Sth, 29th. 



Last Frost, 4th. 



Thunder and Lightning, ist, 28th. 



Qales, 35 miles or more per hour, 46 m., ist, 



S.S.W. ; Z7 m-. 3d, S.S.E. ; 36 m.,9th, N. ; 



42 m., 14th, N.; 39 m., 24th, N.N.W. ; 35 



111., 30th, W.N.W. 



