METEOROLOGICAL OBSERVATORY 



Hatch Experiment Station 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



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



Height of barometer above ground, 51 f^- Above sea level, -73-5 f^- 

 Height of Wind Instruments 72 ft. 



BULLETIN No. 139. 



JULY, 1900. 



MONTHLY SUMMARY. 



I'reasttre. In inches. 



Maxiniiiniiediiced to fioezing, 29.87,22(1,7 A. 

 Mininuini lechiced to freezing, 29.14, Sth, 5 p. 

 Reduced I niaxiniiim reading, 30.16, 22d, 7 A. 

 Kediicecil minimum reading, 29.42, Sth, 5 p. 



Me. m tri-d, lily reduced, 29.914 



.Monthly range • 73 



*Air Temperature. In Degrees Fahr. 



Highest, 95-5. 17th, 3 p. 



Lowest, 44.5, 2d, 5 A. 



.Mean liourly, 70.6 



Mean of means of max. and min., . . . .71.5 



.Mean sensiljle (wet bulb), 63.0 



Monthly range 51.0 



Highest mean daily, 84. o, 17th 



Lowest mean daily 61.2, ist 



Mean maximum, 84. o 



Mean minimum, 59.1 



Mean daily range, 24.9 



Greatest daily range, 34.0, 2d, nth 



Least daily range, 9.0, 26th 



Miitnidit!/. 



.Mean dew point, 62.3 



Mean force of vapor 847 



Mean relative humidity, . . . • ... .71.1 



Precipitation. In inches. 



Total precipitation, . • 4.67 



.\'umlx;r of days on whicii .01 inch or more 

 rain or melted snow fell, 12 



* Temperature in ground shelter, 

 t Reduced to freezing and sea-level. 



Wind. 



Total movement, 3701m. 



Greatest daily movement, 225 ni., ist 



Least daily movement, i9"i., zSth 



Mean daily- movement 119 m. 



Mean hourly velocity, 5 m. 



Maximum pressure per square foot, 23 lbs.= 



68 ni. per hour, 7th, 4 p., S. \V. 

 Prevailing Direction, W.S.W. 

 Summary. 



Southwest, 10 per cent. 



South, 26 " " 



Northwest, 26 " " 



Other directions, .38 " " 



Weather. 



Mean cloudiness observed, .... 48 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, 203 hrs.=44 per cent. 



Number of clear days, ir 



Number of fair days, 10 



Number of cloudy days, 10 



Jtriffht Sunshine. 



Number of hours recorded, . . . 260 hrs. = 5656 

 Hain, 3d, 6th, 7th, Sth, 9th, 12th, 15th, i;th, 



iSth, 20th, 21st, 24th, 25th, 26th, 30th. 

 Thunder and Jjightning, 6th, Sth, 12th, 



15th, 18th, 20th, 2tst. 



Hail. i2th. 



Gales, 35 miles or more per hour, 36m., ist, 



N. N. W. ; 36m., 3d, S. W.; 6Sm., 7th, S. 



W.; 36m. nth, W. S. W.; 44 m. 12th, S. 



W.: 39 m., i;th, VV.: 39ni., iSth, N. \V. 



