METEOROLOGICAL OBSE^RVATORY 



OF THE 



Hatch Experiment Station, 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



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



Height of instruments above ground^dlft. Above sea levels 273.5 ft. ** 



BULLETIN No. 120. 



DECEMBER, 1898. 



MONTHLY SUMMARY. 



Pressure. In inches. 

 Maximum reduced to freezing, 30.19, 16tli,7A. 

 Minimum reduced to freezing, 28.82, 5th, lA- 

 Reduced! maximum reading, 30. .52, 16th, 7a. 

 Reduced! min. reading, .... 29.13, 5th, lA. 



Mean reduced!, 29.963 



Monthly range 1.39 



*Air Temperature, In Degrees Fahr. 



Highest 48.0,.'i0th, 3P. 



Lowest, — 12.0, 14th,6A. 



Mean, : • ■ • -262 



Mean of means of max. and min., .... 25.8 

 Mean sensible(wet bulb) 25.1 



Monthly Range, 60.0 



Highest mean daily, 38.3, 23d 



Lowest mean daily 7.8, 14tli 



Mean maximum, 34.8 



Mean minimum 17.1 



Mean daily range, 17.7 



Greatest daily range, 30.5, 16th 



Least daily range, 4.5,11th 



Humidity. 



Mean dew point 20.8 



Mean force of vai)or 1.56 



Mean relative humidity 80.2 



Wind. 



Prevailing Direction, West. 



Summary. 



West, 17 percent 



South West 13 " " 



South 13 " " 



.South South West lu " " 



North West ... 10 " " 



North 10 " " 



Other directions 25 per cent. 



Total movement 4830 m. 



Greatest daily movement, . . . 427 m., 5th 



Least daily movement 5m.,10d 



Mean daily movement, 156 m. 



Mean hourly velocity, 6.5 m. 



Maximum pressure per square foot, 2Slb8 = 



75m. per hour, 4th, I2a., E.S.E. 

 frecipitation. In inches. 



Total precipitation, 2.30 



Number of days on which .01 inch or more 



rain or melted snow fell, 9 



Snow total in inches H 



Snow on ground at end of mouth . . 3 inches 



Weather. 

 Mean cloudiness observed, . . 66.0 per cent. 

 Total cloudiness recorded by the Sun Ther- 



mometer, . . . 170 hours or 60.0 per cent. 



Number of clear days 5 



Number of fair days, 12 



Number of cloudy days, 14 



Brifflit Sunshine. 

 Number of Hoiii-s recorded, 113 hours or 40)( 

 JBaiH,4th, 5th, litth, 20th, 21st, 22d, 23d, 



31.st, 24th, 

 Sleet, 4th, 22d. 



Snoto, 5th, 8th, lOtli, 20th, 27th, 29th, 31th. 

 Gales, of 35 or more miles per hour, 41m., 

 1st, W.N. W. ; 75ni, 4th, E.S E.; 73m, 5th, E. 

 S.E. ; 47th, Gth, N.W. ; 40m, 8th, N.W. ; 43m., 

 10th., W. ; 40m, 11th. W. ; 36m, 2:!d., N.W. ; 

 45m. 28th., N. W.; 50m, 31st., N.N.E. 

 No. days sleighing 14 



* Temperature in ground shelter. 



! Reduced to freezing and sea level. 



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



