METEOROLOaiCAL OBSERVATORY 



Hatch Experiment Station, 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



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



Height of instruments above ground, 51ft. Above sea level, 273.5 ft. ** 



BULLETIN No. I 13. 



MAY, 1898. 



MONTHLY SUMMARY. 



Pressure. In inches. 

 M.aximum reduced to freezing, 30.03, 22d, 7a. 

 Minimum reduced to freezing, 29.28, 7th, 5p. 

 Rcducedt maximum reading, 30.33. 22d, 7a. 

 Reduced! rain, reading, .... 29.67, 7th, 5p. 



Mean reduced! 29.937 



Monthly range 75 



*Air Tetnperature. In Degrees Fahr. 



Highest 78.5, 20th, ;12M 



Lowest 32.5, 10th, 5a 



Mean 55.0 



Mean of means of max. and min., .... 65.3 



Mean sensible(wet bulb) 52.2 



Monthly Range, 46.0 



Highest mean daily 70.2, 20th 



Lowest mean daily, 41.8, 4th 



Mean maximum, 64.7 



Mean minimum 45,9 



Mean daily range iS.8 



Greatest daily range 36.5, 7th, 10th 



Least daily range 5.0, 3d 



Humiditt/. 



Mean dew point 48.8 



Mean force of vapor, 470 



Mean relative humidity 78.4 



Wind. 



Prevailing Direction, South South West. 

 Summary. 

 North 13 per cent- 

 South, 29 " " 



North East 10 " " 



North North East 10 " " 



Other directions, 38 " " 



Total movement, 4769 m. 



Greatest daily movement, . . .590 m., 8th 



Least daily movement 37 m., 15th 



Mean daily movement, 153.8 m. 



Mean hourly velocity, 6.4 m. 



Maximum pressure per square foot, 18.0 lbs = 

 60 m. per hour, 10 A., 8ih, N.E. 



Precipitation. In inches. 



Total precipitation, 5.61 



Number of days on which .01 inch or more 



rain or melted snow fell, 14 



Weather. 

 Mean cloudiness observed, . . 65.0 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, . . . 2.53 liours or 56.0 per cent. 



Number of clear days 7 



Numberof fair days, li 



Number of cloudy days IS 



Priffht Sunshine. 

 Number of Hours recorded, 20(i hours or 44?( 

 Katn, 2d,3d,4th,.ith,Ilth,12th, 1.5th, 16th, 19th> 

 23d,24th,25th,26th,27th,2bth,2Wth,31th. 



Snow, ^ 2d, frth, 6t h . 



Hail, , lOth.'iSth.., 



Thunder and lightning, . . . . 12th, 19th. 

 Gales, of 35 or more miles per hour, 40m .,1st 

 N.N. E.;60m., 8th, N. E.;37m., 11th, S.; 

 47m., 12th, S.; 35m., 17th, W. 



* Temperature in ground shelter. 



t Reduce<i to freezing and sea level. 



♦ * Determined from levels of B. & M. R. R. 



