No. 4.] MASSACHUSETTS WEATHER. 



XXXI 



Meteorological Observatory of the Hatch Experi- 

 ment Station (Massachusetts Agricultural Col- 

 lege), Amherst. 



[Latitude, 42° 23' 48.5" N.; longitude, 72' 31' 10" W. Ilciglit of barometer above ground, 

 51 feet; above sea level, 273.5 feet. Height of wind instruments, 72 feet.] 



Annual Summary for 1905. 



Pressure (in Inches). 



Maximum reduced to freezing, 30.34, 



December 1, 11 A.M. 

 Minimum reduced to freezing, 28.01, April 



6, 10 a.m. 

 Maximum reduced to freezing and sea 



level, .80.80, Decemljer 1, 11 a.m. 

 Minimum reduced to freezing and sea 



level, 29.22, April 6, 10 A.M. 

 Mean reduced to freezing and sea level, 



30.019. 

 Annua! range, 1.04. 



Air Temperature {in Decrees F.).^ 



Highest, 93.0, July 10, 2.30 p.m. 



Lowest, —13.0, January 24, 7.30 a.m. 



Mean, 45.8. 



Mean of means of max. and min., 40.1. 



Mean sensible (wet bulb), 41.1. 



Annual range, lOG.O. 



Highest mean daily, SI .5, July 18. 



Lowest mean daily, 1.7, January 5. 



Mean maximum, 57.1. 



Mean minimum, 35.0. 



Mean daily range, 22.1. 



Greatest daily range, 45.0, June 9. 



Least daily range, 3.0, June 12. 



Humidity. 



Mean dew point, 37.3. 

 Mean force of vapor, .305. 

 Mean relative humidity, 70.5. 



Wind. — Prevailing Direction, West. 

 Summary {Per Cent), 

 West, north-west, 13. 

 South, south-west, 11. 

 South, 10. 

 North-west, 9. 

 West, S. 



Other directions, 49. 

 Total movement, 46,442 miles. 



Greatest daily movement, 475 miles, Jan- 

 uary 4. 



Least daily movement, 1 mile, June 22. 



Mean daily movement, 127 miles. 



Mean liourly velocity, 5.3 miles. 



Maximum pressure, per square foot, 23.5 

 pounds = 69 miles per hour, January 

 4, 9 A.M., W.N.W. 



Precipitation {in Inches) . 

 Total precipitation, rain or melted snow, 



38.80. 

 Number of days on which .01 or more 



rain or melted suow fell, 122. 

 Snow total, in Indies, 40.0. 



Weather. 



Mean clotidiness observed, 49 per cent. 

 Total cloudiness recorded by sun ther- 

 mometer, 1,977 hours — 44 per cent. 

 Number of clear days, 130. 

 Numl)er of fair days, 128. 

 Number of cloudy days, 107. 



Bright Sunshine. 

 Number of hours recorded, 2,477 = 56 per 



cent. 



Dates of Frosts. 



Last, May 24. 

 First, Septemljer 15. 



Dates of Snoiu. 



Last, INfay 1. 



First, November 9. 



Total days of sleighing, 64. 



Gales of 50 or More Miles per Hour. 

 January 4, 09 miles, N.N.W.; 7, 52 miles, 



E.S.E.; 25, 60 miles, N.N.W.; 26, 50 



miles, N.W. 

 February 18, 60 miles, W. 

 March 19, 57 miles, N.E. 

 April 17, 60 miles, W. 

 December 30, 53 miles, W. 



1 Temperature in ground shelter. 



J. E. OSTRANDER, Meteorologist. 

 C. H. CHADWICK, Observer. 



