METEOROLOGICAL OBSERVATORY 



Hatch Experiment Station, 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



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



Height of instruments above ground,51ft. Above sea level, 273.5 ft. ** 



BULLETIN No. I 17. 



SEPTEMBER, 1898. 



MONTHLY SUMMARY. 



Pressure. In inches. 

 Maximum reduced to freezing, 30.11, 13th, 7a. 

 Minimum reduced to freezing, 20.3', 23d,. 5p. 

 Reducedt m.i.vimum reading, 30.41, 13th, 7a. 



Reducedt min. reading 29.59, 23d, 5p. 



Mean reduced!, .... 30.012 



Monthly range, S2 



*Air Temperature. In Degrees Fahr. 



Highest 93.0, 3d, 3p. 



Lowest, 34.5, 21st, 6a. 



-Mean, 63.0 



Mean of means of max. and min 63.6 



Mean sensible(wet bulb) 59.8 



Monthly Range 58.5 



Highest mean daily, 78.5, 3d 



Lowest mean daily 49.9, 2r)th 



Mean maximum, 76.2 



Mean minimum 51.1 



Mean daily range 25.1 



Greatest daily range 36.5, 2Sth 



Least daily range 10., 25th 



Humiditi/. 



Mean dew point 56.9 



Mean force of vapor 640 



Mean relative humidity, 80.0 



IVind. 



Prevailing Direction, South West. 



Summary. 



South South West 17 per cent. 



South, 17 " " 



South West, 23 " 



West, _ 17 per cent. 



Other directions 26 " " 



Total movement, 2787 m. 



Greatest dally movement, . . . 220 m., 22d 



Least daily movement, 27 m., 9th 



Mean daily movement, 92.9m. 



Mean hourly velocity 3.9 m. 



Maximum pressure per square f oot,30.5 lbs = 

 78m. per hour, 7th. 1 30 p., S. W. 

 Precipitation. In inches. 



Total precipitation 3.65 



Number of days on which .01 inch or more 



rain or melted snow fell, 7 



Weather. 



Mean cloudiness observed, . . 48.0 per cent. 



Total cloudiness recorded by the Sun Ther- 

 mometer, . . . 154 hours or 42.0 per cent. 



Number of clear days 9 



Number of fair days, 14 



Number of cloudy days, 7 



Uright Sunshine. 



Number of Hours recordeil, 218 hours or 5S?S 



Rain, 1st, 2d, 4th, 7th, lf;th,lSth,22d,L'3d,24th. 



Thunder and lightning, 1st, 2d, 4th, 6th, 

 7lh, 18th, 23d. 



Hail, 7th. 



Atirora, itth. 



Frosts on lotvlands , 2l8t, 2Sth. 



Oales, of 35 or more miles per hour, 48m., 

 2(1, N.W. ; 78m., 7th, 8.W.; 35m., 20th, W. 

 N.W.; 44m., 27th, N.W. 



* Temperature in ground shelter. 



t Reduced to freezing and sea level. 



* * Determined from levels of B. & M. R. U. 



