ey 
694 TRANS. OF THE ACAD. OF SCIENCE. 
far from the Pacific Railroad ee Te shop. His average for ie whole 
year shows 1°.4 less than the c It is that much warmer in the high 
and dry and somewhat sheltered ¢ city locality, than in the rather ow val- 
ley. The difference at 9 0 *. M. was the greatest, viz., 2°.1; at 
evident that the greater clearness of the sky and with it the greater evapo- 
ration and Sha ation produced the Acc Tall of the thermome wel in that 
valley, as as, no danke ta in all similar situations. e same fact is 
evident f tity the daccah bps that in cloudy weather there wa st Title if 
he clearness of sky was last year beyond the average. e clear 
est months were, as abov 8 ee Ff july, October and August; the cloudi- 
est, December and M peg (5.5 an siderabl 
With all this clearness the quantity Ne rain. ane snow was cons Saag 
above an average one, amounting to over 61 inches (scarcely 9 ine oe - 
prs in the excessively wet year 1858), only 3 inches of whic rf fe 
now. The driest months were October (1.80), January and August; 
watasat: June 2 inches). 
esterly a prevailed, as usual, in the colder, and south- easterly in 
the beg Het months of last year. ratare of 
r. Engelmann also ona a asd for the average tempera pers 
every month in the last twenty-five years, and promised to continue ans 
extracts nck his ihetacedldgical Journals, font now for more than a 
ter of a century. 
Col. W. Gilpin presented to the Academy a Hydrographic 
Map of N. America, a Map of the Basin of the Mississippi, 
and an Isothermal Chart, constructed and drawn by apes ; 
and made some explanatory remarks touching his views of 
matters represented therei 
February 6, 1860. wag 
The President, Dr. H. A. Prov, in the chair. 
Eleven members prese : 
Letters were read from —e K. bayer. Akad. d. Wissensch., 
