METEOROLOGICAL OBSERVATORY 



Hatch Experiment Station, 



. MASSACHUSETTS AGRICULTURAL COLLEGE 



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



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



BULLETIN No. 40. 



APRIL, 1892. 



MONTHLY SUMMARY. 



Pressure. In inches. 

 Actual maximum reading, . . 30.24, lat, 10 a. 

 Actual minimum reading, . . 29.215, 9th, 3 P 



Mean reduced to sea level 29.972 



Monthly range, 1.025 



*Air TemperaUtre. In Degrees Fahr. 



Highest 72; 7S.5 



Lowest 27; 20.5 



Mean, 48.7; 45. 



Monthly Range, 45. ; 58. 



Highest mean daily, 63.8; 62. 



Lowest mean daily, 37.5; 35.8. 



Mean maximum, 56.9; 58.6 



Mean minimum, 39.1; 31.9 



Mean daily range, 17.7 ; 26.7 



Greatest daily range, 33. ; 42. 



Least daily range, 2; 12. 



Humidity. 



Mean dew point 33. 



Mean force of vapor, 37V6 



Mean relative humidity, . . .'i4.5 



Wind. 

 Prevailing Directions. 



North West 24 per cent. 



South West 11 " 



West North West 10 " 



North East, 10 " " 



Other directions 45 " " 



Total movement 5370m 



Greatest daily movement 349 m., 11th 



Least daily movement, 60ni., 4th 



Mean daily movement 179 m 



Mean hourly velocity 7.5 m. 



Maximum pressure per square foot, 16Jll)s.= 

 58 m. per hour, 11th, at 2 P. 



* Precipitation. In inches. 



Total precipitation, 54 ; .76 



Wenther. 



Mean cloudiness observed, . . .42 per cent. 



Number of clear days, 17 



Number of fair days, 6 



Number of cloudy days, 7 



Total cloudiness recorded by the Sun Ther- 

 mometer, . . . 158 hours or 39 per cent. 

 Number of days on which .01 inch or more 



rain or melted snow fell, 3 



Number of inches of snow on the ground at 

 the close of the month, 



Bright Sunshine. 



Number of Hours recorded 244 



Rain. . 2d, 4th, 5th, 21st, 22d, 23d, 28th, 29th. 



Snow, 10th. 



Total fall in inches T 



Aurora Jiorealis, 23d, 24th, 25th, 26th, 29th. 



Mean Ozone, 29 per cent. 



Malos. 

 Solar, . . . 3d, 5th, 7th, 8th, 14th, 15th, 25th. 



Lunar 3d, 7th. 



Corona, 4th, 10th. 



Gales, of 50 or more miles per hour, . .53, 6th, 



N. W.; 54, 10th, W.; 58, 11th, W.N. W.; 



51, 15th, N.E. 



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



