METEOROLOGICAL OBSERVATORY 



OK THE 



Hatch Experiment Station 



MASSACHUSETTS AGRICULTURAL COLLEGE 



Latitude, 42° 23' 48.:)" N. Longitude, 72" 31' 10" W . 



Height of instruments above ground^ 51 ft. Above sea level, 260 ft. 



BULLETIN No 36. 



DECEMBER, 1891 



MONTHLY SUM/nARY. 



yresxKfe. In inches. 

 Actual maximum reading, . .'50. 25, 31st, 9 P. 

 Actual niiiiimum reading, . •J9.02."), 16th, 7 A. 



Mean reduced to sea level, 30.081 



Monthly r.Tng-e, . ].22.'i 



*Air Temperature. In Degrees Fahr. 



Highest .1(5.5; «0.5 



Lowest, 14: 9. 



Mean, 38.3; 36.9 



Monthly Range, 42.5; 51.5 



Highest mean daily, 51.; 46.5 



Lowest meau daily, 17. S; \<o 



Mean maximum, 45.2; 4' 



Mean minimum, 32.4; 26.3 



Mean daily range, 12.8; 21.2 



Greatest daily range, 25.5; 31.5 



Least daily range, 2; 6.5 



rfiiniiftiti/. 



Mean dew point, 28.2 



Mean force of vai)or, 2483 



Mean relative humiditV: 68.7 



Wind. 



Prevailing Directions. 



North West, 20 per cent. 



South, 18 " 



North, 17 " 



.South, .South West, 13 " " 



Other directions 32 " " 



Total movement, .5465 m. 



Greatest daily movement, . . . 390m.,30tli- 



Least daily movement, 20m., 21st. 



Mean daily movement, 176.3 m. 



Mean hourly velocity, 7.3 m. 



Maximum pressure per square foot, 14 lbs. = 

 .53 m. per hour, 16th, at 10-.30 a.m. 



* Precipitation. In inches. 



Total pi-ecipitatiou, 3.62 ; 5.40 



Weather. 

 Mean cloudiness observed, . . . 51 per cent. 



Number of clear days, 12 



Number of fairdays, 10 



Number of cloudy days 9 



Total cloudiness recorded by the Sun Ther- 

 mometer, ... 141 hours or .50 per cent. 

 Number of days on .which .01 inch or more 



rain fell, 10 



Bright Sunshine, 



Number of Hours recorded, 143 



Jtain, 4th, 7th, 15th, 16th, 22d, 23d, 24th, 26tb, 

 29th, 30th. 



Snoif, 16th, 29t!;. 



Hail, 1.5tl.. 



Mean Ozone, .36percen'. 



Itdlolt. 



Solar, 2d, 18ih, llJtli 



Lunar 9th, 12th, 19tli- 



Coronae 9th, 11th, 14th, 16th. 



Qalen, of 40 or more miles per hour, 40, 4th, 

 S. W.; .53.16th, \. 



♦The first figures denote r(^■lllings at top of tower, the second at base. 



