METEOROLOGICAL OBSERVATORY 



Ilatcli Experinient Station, 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



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



Height of instruments above gronnd^Slft. Above sea level, 27S.5 ft. ** 



BULLETIN No. 103. 



JULY, 1897. 



MONTHLY SUMMARY. 



Pressure. In inches. 

 Maximum reduced to freezing, 30.04, 19th, 7a. 

 Minimum reduced to freezing, -iO.S."?, 12th, 4 p. 

 Reduced! maximum reading, 30.33, li)th, 7 A. 

 Reducedf min. reading, . . . 29.61, l-2th, 4 p. 



Meanreducedf, . . .29.943 



.Monthly range 0.72 



*Air Temperature. In Degrees Fahr. 



Higliest 91.; 6th, 9t)i 



Lowest 55., 1st, 27th 



Mean, 70.5 



Mean of means of max. and min., .... 71.(! 



Mean sensible(wet bulb) 67.1 



Monthly Range 36. 



Highest mean daily, 78.1,9th 



Lowest mean daily, 60.5, 29th 



Mean maximum, 81.0 



.Mean minimum, 62.3 



Mean daily range, 18.7 



Greatest daily range 29., 16th 



Least daily range, 4., 13th 



II uinidity . 



Mean dew point 64.8 



Mean force of va))or 787 



Mean relative humidity 80. S 



Wind. 



Prevailing Direction, South. 



Summary. 



South 42 per cent. 



South, South West, 13 " " 



North 10 " " 



Other directions, 35 " " 



Total movement 4007 m. 



Greatest daily movement, . . . 317 m., 14th 



Least daily movement 36 m., 16th 



Mean daily movement, 129.3 m. 



Mean hourly velocity, 5.4 m. 



Maximum pressure per square foot, 12 lbs.= 

 49 m. per hour, 7 p., 14th, W. 



Precipitation. In inches. 



Total precipitation 14..51 



Number of days on which .01 inch or more 

 rain or melted snow fell, 14 



Weather. 



Mean cloudiness observed, ... 64 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, . . . 249.0 hours or 54 per cent. 



Number of clear <lays, 5 



Number of fair days, 13 



Number of cloudy days, 13 



Jtriffht Sunshine. 



Number of Hours recorded, 214 hours or 46?$ 

 Rain, 2d, 3d, (ith, 7tli, 12th, I3th, 14th, 



17th, 18th, 19th, 22d, 23d, 24th, 2.5th, 2(;th, 



27th, 28tb, 29th. 

 Gales, o{ 35 or more miles per hour, 36m., 



13th, S.S.E. ; 49 m., 14th, W. ; 47 m., 23d, 



S.W. 

 Thunder and liigJttning, 6th, 7th, 14th, 23d 

 Hail, 14th, 23d 



* Temperature in ground shelter. 



t Rcfluced to freezing and sea level. 



* * Determined from levels of II. & M. R. R. 



