BULLETIN No. 24. DECEMBER, 1890. 



METEOROLOGICAL OBSERVATORY 



Ol' IIIK 



llatcli Experiment Station, 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



Latitiide. 42° 23' 48.5" N. l.oiigitude, 72° 31' 10" W. 



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



MONTHLY SUMMARY- 



I'rr.ssiirc. In inches. Actual maximnni reading ;^0.20; actual minimum reading 29.115; 

 Mc:m reduced to sea level, 30.013; JJonthly Uange, 1.175 in. 



*.!/»■ T'lupfiatine. In Dearrees Fahrenheit. Highest, 42..5>^; 43.5"; Lowest, 2^ —5"; 

 Mean, -li.ii-^ -il.S^; .Monthly lluige, 40.5^ 4«!..')-'; Highest Moan D:iilv-, 3(5.3-', 3(i..i>'; Lowest 

 Mean Dailv, S.-2'-\ S.4-; Mean Maximum, •29.5'^. 31''; Mean Mininnini, 15 S'', 12.G''; Jlean Daily 

 Range. 13.(i, Ls.!"^; Greatest Daily Range, 2.3-'; 35.5--'. Least Daily Range, 5-^; 8'^. 



Hum hi it ft. J[eau Dew Point, 14.7-'; Mean Force of Vapor, .1400; Mean Relative 

 Humidity, 07 2. 



Wiii,l. Prevailing Directions, N. W. 30 per cent., N. 16 per cent., S. W. 12 per cent., 

 N.N.W. 9 per cent., other directions 33 per cent.; Total Movement. .5()73 miles; Greatest 

 Dailv Movement, 325 m., 17th: Least Dailv Movement, 43 ni.9th; Mean Daily Movement, ]!?3 

 niik-s; Mean Hourlv V'elocity, 7.6 miles;' Maximum Pressure per Square Foot, 24^ lbs.= 

 70 m. per hour, 4th, at 9-30 A. M. 



Pretipitation. In inches. Total Precipitation, 1.18 in. ; at base of tower 2.86 in. 



iriatlier. Mean Cloudiness observed,. 53 percent; Number of Clear Days, 15; Number 

 of Cloudv Havs, 11; Number of Fair Davs, 5; Total Cloudiness recorded by the Sun 

 Thernu)meter, "1.53 hrs., or .54 per cent. Number of days on which .01 inches or more rain 

 or snow tell, 9. Depth of snow, in inches, on ground at close of month, 10 in. 



Briijht Sunshine. Number of Hours Recorded, 131. 



Stiotr, 3d. .5th, 6th, 17th, i8th, 22d, 26th, 27th, 29th. 30th. Total fall in inches, 15J. Haib 

 3d, 6th, 2Tth. Rain, 3d, 6th, 17th, ISth, 21st, 22d. 



Mean Ozone, 39 per cent. 



Halos, Lunar, 16th ; 25th; Lunar corona, 23d, 24th, 29th, 30th. 



Gale.'i, 2d, 4th, 7th, 12th, 17th, 18th, 19th, 22d, 24th, 2Stli. 



DAILY SUMMARY- 



Dec. 1. Barometer reduced to sealevel, max. 29.725, miii 29.545, mean 29.62. 



♦Temperature, max. 35.5^, 38", 2 a.m., min 13.5°, 15", 12 p.>i., mean hourly 23°. 



Snn Thermometer, bright sunshine 3 hrs. 



Mean dew point 4.3^, mean force vapor .1123, mean humidity 49.7. 



Wind, N.W., total movement, 248 m., mean hourly velocity 10.3 m., max. pres- 

 sure, 4 1-2 lbs. =30 m. per hour, 7-30 a.m. Ozone 40. 

 2. Barometer reduced to sea level, max. 30.3, min. 29.725, mean 30. 



Temperature, max. 19^, 21°, 2 p.m., min. 8*^, 4°, 12 p.m., mean hourly 12.8°. 



Sun Thermometer, bright sunshine 6 hrs. 



Mean dew point -1.7'', mean force vapor .0818, mean humidity 54. 



Wind, N.W., total movement 171 m., mean hourly vel. 7.1 m., max. pressure 

 6 1-4 lbs.= 35 m. per hour, 3 p.m. Ozone 20. 

 3 Barometer reduced to sea level, max. 30.41, min. 29.69, mean 30.168. 



Temperature, max. 21°, 21°, 12 p.m., min. 5°, 2.5°, 2 a.m., mean hourly 10.5°. 



Snn Thermometer, bright sunsliine 0. 



Mean dew point 6.3°, mean force vapor .0901, mean humidity 69.3. 



Wind, X.W., total movement 125 m.. mean hourly vel. 5.2 m., max. pressure 

 1 1-4 lbs. = 16 m. per hour, 8 p.^t. Snow began falling about 9 a.m. The 

 storm continued throughout the day with hail and flue rain in the evening. 



*The first figures denote readings at top of tower, the second at base. 



