226 MASS. EXPERIMENT STATION BULLETIN 270 



Greatest monthly movement, April, 1908 8,208 



Least monthly movement, July, 1894 1,109 



Mean monthly movement 4,358 



Greatest daily movement, April 8, 1909 705 



Least daily movement, Sept. 29, 1894 ; Mar. 7, 1890 ; Jan. 6, 1904 ; 



Dec. 4, 1916 ; Oct. 6, 1920 



Mean daily movement 143 



Alaximum velocity for 5 minutes, Feb. 22, 1912, 10 a.m 42 



Weather 



Mean cloudiness observed, per cent 50.8 



Total number of hours bright sunshine 94,236 



Per cent of possible hours bright sunshine 53 



Number of clear days 4,399 



Number of fair days 5,165 



Number of cloudy days 5,152 



Publication of this Document Approved by Commission on Administration 



AND Finance 

 2m-4'31. No. 2143 



I 



