METEOROLOGICAL OBSERVATORY 



OF THE 



Hatch Experiment Station, 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



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



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



BULLETIN No. 53. 



MAY, 1893. 



MONTHLY SUMMARY. 



Pressure. In inches. 

 Actual maximum reading, . . 30.03, 9lh, 7 A. 

 Actual minimum reading, . . 28.87, 4tli, 2 r. 



Mean reduced to sea level 29.895 



Monthly range • • l-l^ 



*Air Temper aUtre. In Degrees Fahr. 



Highest 90, 87, llth 



Lowest 38, 30, 8th 



Mean, 58.7; 55.8 



Monthly Range 52. ; 57. 



Highest mean daily 72.8; 70.5 



Lowest mean daily, 44.2 ; 43.5 



Mean maximum 67.7; C8.3 



Mean minimum, 49.7 ; 43.3 



Mean daily range 18. ; 25. 



Greatest daily range, 36. ; 45. 



Least daily range, 5. ; 1 1 . 



Hinnidity. 



Mean dew point 45.7 



Mean force of vapor 5110 



Mean relative humidity, G6. 



Wind. 



Prevailing Directions. 



North West 14 per cent. 



South, 12 " 



South West, 12 " " 



East, 11 " " 



Other directions 51 " " 



Total movement, 4833 m. 



Greatest daily movement, . . . 338 m., 4th. 



Least daily movement, 49 m.; 14th 



Mean daily movement, 150 m. 



Mean hourly velocity, 6.5 m- 



Maximum pressure per square foot, 2451b8.=: 

 71 m. per hour, 4th, <at 4-30 a. 



* Precipitation. In inches. 



Total precipitation, 3.17; 5.02 



Weather. 



Mean cloudiness observed, . . .55 per cent. 



Number of clear days, 8 



Number of fair days, 7 



Numljer of cloudy days 16 



Total cloudiness recorded by the Sun Ther- 

 mometer, . . . 265 hours or 59 per cent. 

 Number of days on which .01 inch or more 

 rain or melted snow fell, 17 



Frost, . 



. 7th, 8th. 



Bright Sunshine. 



Number of Hours recordeil, 188 



Rain, . . 1st, 2d, 3d, 4th, 5th, fith, 13th, 14th, 

 16th, 17tli, 18th, 23d, 24th, 26th, 27th, 30th, 

 31st. 



Aurora Rorealis, 7th. 



Thunder and Lightning, . . . .23d, 30th. 



Mean Ozone, 32 per cent. 



Hidos. 



Solar, 2d, 10th, 20th, 23d, 25th, 20th. 



Lunar, 22d, 28th. 



Onles, of 35 or more miles per hour, 37, 3d ; 

 N.E.;71, 4th, N.E.; 46, 5th, W.N.W.; 37, 

 13th, N.N.E.; 47,16th, E.S.E.; 46, 2l8t, 

 N.W; 36, 23d, S.W.; 48, 25th, S.W.; 44, 

 28th, N.W. 



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



