No. 4.] 



REPORT OF SECRETARY. 



xv 



Meteorological Observatory of the Hatch Experi- 

 ment Station (Massachusetts Agricultural Col- 

 lege), Amherst. 



Annual Summary for 1898. 



Pressure (in Inches). 



Maximum reduced to freezing, 30.45, 

 March 26, 7 A.M. 



Minimum reduced to freezing, 28.69, Feb- 

 ruary 19, 6 A.M. 



Maximum reduced to freezing and sea 

 level, 30.76, March 26, 7 a.m. 



Minimum reduced to freezing and sea 

 level, 29.01, February 16, 6 a.m. 



Mean reduced to freezing and sea level, 

 30.008. 



Annual range,* 1.75. 



Air Temperature (in Degrees F.).* 

 Highest, 96.5, July 3, 3 P.M. 

 Lowest, — 19.0, February 3, 6 a.m. 

 Mean, 47.5. 



Mean of means of max. and min., 47.5. 

 Mean sensible (wet bulb), 45.2. 

 Annual range, 115.5. 

 Highest mean daily, 81.6, July 3. 

 Lowest mean daily, —2.0, January 30. 

 Mean maximum, 57.7. 

 Mean minimum, 37.4. 

 Mean daily range, 20.3. 

 Greatest daily range, 40.0, February 3. 

 Least daily range, 2.5, April 5. 



Humidity. 

 Mean dew point, 4.16. 

 Mean force of vapor, .426. 

 Mean relative humidity, 79.8. 



Wind. — Prevailing Direction, West, or S. 



86° W. Summary (Per Cent). 

 South, 15. 

 West, 13. 

 North-west, 12. 

 South-south-west, 11. 

 South-west, 10. 

 North, 9. 



Other directions, 30. 

 Total movement, 48,425 miles. 

 Greatest daily movement, 675 mile6, No- 

 vember 27. 



Least daily movement, 4 miles, January 

 18. 



Mean dally movement, 133 miles. 



Mean hourly velocity, 5.5 miles. 



Maximum pressure per square foot, 30.5 

 pounds = 78 miles per hour on Sep- 

 tember 7, 1.30 p.m., S.W. 



Precipitation (in Inches). 



Total precipitation, rain or melted snow, 



53.89. 

 Number of days on which .01 or more 



rain or melted snow fell, 135. 

 Snow total in inches, 69.5. 



Weather. 

 Mean cloudiness observed, 60 per cent. 

 Total cloudiness recorded by sun ther- 

 mometer, 2,317 hours = 52 per cent. 

 Number of clear days, 78. 

 Number of fair days, 138. 

 Number of cloudy days, 149. 



Bright Sunshine. 

 Number of hours recorded, 2,159= 48 per 

 cent. 



Dates of Frosts. 



Last, April 27. 

 First, September 21. 



Dates of Snoio. 



Last, April 6. 



First, November 24. 



Total days of sleighing, 85. 



Gales of 50 or More Miles per Hour. 

 January 3, 67 miles, N.W.; January 24, 

 56 miles, N.W.; March 20, 56 miles, 

 W. ; May 8, 60 miles, N.E. ; July 30, 

 59 miles, S.W.; August 23, 51 mile.-, 

 N.W.; September 7, 78 miles, S.W.; 

 November 11, 55 miles, W. ; Novem- 

 ber 27, 62 miles, N. ; December 4, 75 

 miles, W.; December 5, 73 miles, 

 E.S.E.; December 31, 50 miles, N.N.E. 



J. E. Ostkander, Meteorologist. 

 A. C. Moxahas, Observer. 



Temperature in ground shelter. 



