METEOROLOGICAL OBSERVATOHY 



OF THE 



Hatch Experiment Station, 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



-A-IvIKCEE-ST. 



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. 55. 



JULY, 1893. 



MONTHLY SUMMARY. 



Pressure. In inches. 

 Actual maximum reading, . . 29.97, 11th, 8 a. 

 Actual minimum I'eading, . . 29.30, 22nd, 4 P. 

 Mean reduced to sea level, ..... 29.968 



Monthly range, fi7 



*Air Temperature. In Degrees Fahr. 



Highest 90, 90.5, 22nd 



Lowest 51.5,41. 25th 



Mean 71.4; 68.1 



Monthly Range 38.5; 49.5 



Highest mean daily, 80.6; 77.5 



Lowest mean daily, 63.7; .57.5 



Mean maximum 81.9; 82.1 



Mean minimum, 61.1; 54.2 



Mean daily range, 20.8; 27.9 



Greatest daily range, 33. ; 39. 



Least daily range 9. ; 13. 



Buniidity. 



Mean dew point, 58.8 



Mean force of vapor, 8003 



Mean relative humidity 64.8 



Wind. 

 Prevailing Directions. 



Southwest 19 percent. 



South, 15 " 



Xorth West, 12 " " 



North, 9 " " 



Other directions, 45 " " 



Total movement, 3640 m. 



Greatest daily movement, . . . 243 m., 27th. 



Least daily movement 33 m.; 17th. 



Mean daily movement, 117 m. 



Mean hourly velocity, 4.7 m. 



Maximum pressure per square foot, 13 ll)8.= 

 51 m. per hour, 20th, at 7 P. 



* Precipitation. In inches. 



Total precipitation 1.77; 2.59 



Weather. 



Mean cloudiness observed, ... 44 per cent. 



Number of clear days, 10 



Number of fair days 13 



Number of cloudy days 8 



Total cloudiness recorded by the Sun Ther- 

 mometer, . . . 203 hours or 44 per cent. 



Number of days on which .01 inch or more 



rain fell 11 



Bright Sunshine. 



Number of Hours recorded 259 



Rain,. . 1st, 3d, 5th, 8th, 10th, 12th, 17th, 

 22nd, 23tl, 2.5th, 26th, 29th. 



Itainbow, 10th, 26th. 



Thunder and TAghtning, 1st, 3d, 5th, 8th. 

 lOih, 12th, 17th, 18th, 22nd, 25th, 26th. 



Mean Ozone, 19 per cent. 



Solos. 



Solar 22nd, 25th, 28th, 30tb, 31st. 



Lunar 28th. 



Oales, of 35 or more miles per hour, .39, 3d, 

 S. W. ; .39, 6th, N. ; 38, 19th, N. N. E. ; .36, 

 22nd, S. W.; 44,23d, N.W.; 51,26th, N.W.; 

 36, 27th, N. W. 



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



