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 ft. Above sea level, ^'jj.^ ft. 

 Height of Wind Instruments 72 ft. 



BULLETIN No. 187. 



JULY, 1904. 



MONTHLY SUMMARY. 



Pren.^ure. In inches. 

 Maximum reduced to freezing, 29.96, 4th, 6 A. 

 Minimum reduced to freezing, 29.25, 12th, 6 p.. 

 Keducedt maximum reading, 30.26, 4th, 6 A. 

 Keducedt minimum reading, 29.53, 12th, 6 p. 



Mean semi-daily reduced, 29.979 



Monthly range o-73 



*Air Temperature. In Degrees Falir. 



Highest 94-5. I9th, 3 P. 



Lowest 46.5. 4th, 3 A. 



Mean hourly, • 69.8 



Mean. of means of max. and min., .... 70.4 



Mea;i sensible (wet bulb), -64.4 



Monthly range 48.0 



Highest mean daily, •. 7$rS, 'Qth 



Lowest mean daily /• ■ • . '61.0, 23d 



Mean maximum '.^ Si. 6 



Mean minimum; * , . . ..js 59.2 



Mean daily range, 22.4 



Greatest daily range, 33.0, 4th 



Least daily range 7.5, 23d 



H II III ill it If . 



Mean dew point, 61.5 



Mean force of vapor, 720 



Mean relative humidity, 77.7 



Precipitittittn. In inches. 



Total precipitation 2.62 



Number of days on which .01 inch or more 



rain or. melted snow fell, 14 



* I'emperSture in ground shelter. 

 t Reduced to freezing and sea-level. 



Wind. 



Total movement, 3268 m. 



Greatest daily movement, .... 235 m., 31st 



Least daily movement, 9m., 6th 



Mean daily movement 105m. 



Mean hourly velocity, 4.4m. 



Maximum pressure per square foot, 11. o lhs.= 



47 111. per hour, ist, 11 a., S. 

 Prevailing Direction, Southwest. 



Summary. 



South, 32 per cent. 



West Northwest, j6 " " 



West, . . ID " " 



South, Southwest, 10 " " 



Other directions, 32 " " 



Weather. 



Mean cloudiness observed, ..... 55 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, . ..... i88hrs.=4i percent. 



Nuniter of clear days, 12 



Number of fair days, 12 



Number of cloudy days, 7 



Bright Sunshine, 



Number of hours recorded, . . . 274hrs. = 59* 



Rain, ist, 2d, 5th, 8th. 10th, 12th, i8th, 22d, 

 2.3d, 24th, 25th, 26th. 27th, 28th, 29th, 31st. 



6olc«, 35 miles or more per hour, 47 m. ist, 

 S.; 37 m. 2d, W. 



Thuntler and Lif/htning, ist, 5th, 26th. 

 29th. 



