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, 213.5 ft. 

 Height of Wind Instruments 72 ft. 



SEPTEMBER, 1900. 



BULLETIN No. 141. 



MONTHLY SUMMARY. 



Pressure, In inches. 



Maximum reduced to freezing, 30.06, ist, 9 p. 

 Minimum reduced to freezi 0^,29.04, 12th, 10 A. 

 Reducedt maximum readinjf, 30.35, ist, 9 p. 

 Reducedt minimum reading, 29.32, 12th, 10 A. 



Mean tri-daily reduced, 30.035 



Monthly range • 1.03 



*Air Temperature. In Degrees Fahr. 



Highest, S9.0, 6th, 3 p. 



Lowest, 35.5, 19th, 6 A. 



Mean hourly, 63.8 



Mean of means of max. and niin., .... 64.5 



Mean sensible (wet bulb), 58.7 



Monthly range, 53.5 



Highest mean daily, 75.0, 3rd 



Lowest mean daily, 50.5,19th 



Mean maximum, 76.8 



Mean minimum, 52.2 



Mean daily range, 24.6 



Greatest daily range, 37.5, 14th 



Least daily range, 9.0, i6th 



ETtttnidity. 



Mean dew point, 54.7 



Mean force of vapor 646 



Mean relative humidity, ....... .73.1 



Precipitation. In inches. 



Total precipitation, . • 3.67 



Number of days on which .01 inch or more 

 rain or melted snow fell 8 



* Temperature in ground shelter. 

 t Reduced to freezing and sea- level. 



Witid. 



Total movement, 3042m. 



Greatest daily movement, .... 359 m., 12th 



Least daily movement, 21m., 30th 



Mean daily movement 101.4 m 



Mean hourly velocity, 4.2 m. 



Maximum pressure per square foot, 17.0 lbs.= 



60 m. per hour, 12th, 11 A., S. W. 

 Prevailing Direction, South. 

 Summary. 



Southeast, 10 per cent. 



North, 10 " " 



South, Southeast, 20 " " 



South, 20 " " 



Northwest, 10 " " 



Other directions, 30 " " 



Weather. 



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



Total cloudiness recorded by the Sun Ther- 

 mometer, 198 hrs. =53 per cent. 



Number of clear days, 4 



Number of fair days, 12 



Number of cloudy days, 14 



Bright Sunshine. 



Number of hours recorded, . . . 177 hrs.=47J( 



Rain, 6th, i6th, 17th, 18th, 20th, 21st, 22d 

 26th, 29th, 30th. 



TJiunder and Lightning, i6th, 21st, 26th. 



Frost on Low Lands, 15th, 19th. 



Gales, 35 miles or more per hour, 6oni., 12th, 

 S. W.; 35m., 17th, N. W.; 41m., iSth, 

 N.NW.; 35m., 24th, N. 



