ARTS showing the mean Monthly and Annis] Amount of the Diurnal Oscillation of the 
Minimum, by Lines of 10, 20, 40, 60, 80, & 100 (and upwards) thousandths 0, 0'020 inch, &e-} 
“ s 2 5 



from the A.M. Maximum to the P.M. 
N.B.—The Shaded Périions indieate an Oscillation of 0100 inch and upwards 



























































































































































































































































































































































































































































