winters colder, as we go farther west. The annexed table (from 
; ; * 
p: 83) will serve to illustrate this statement, ‘i 
es. eee 
Locality, Latitude, Year. Spring. Summer. Autumn, Winter : 
West Point, N. Y.. 41° 93/ 50°-7 48°7 53°2 
; 713 
Fort Armstrong, Tl, 41 30 50°30 T41 514 ee 
Council Bluffs, 41 30 49 3 49°3 44-7 Sra 3 
1 gs - * . * 
Prairie du Chien, 43 5 : 
Potsdam, N. Y, 4440 43°6 429 668 454 198° 
Fort Snelling, Min, 44 53 446 456 706 459 161 
In the geological portion of the Report, we -notice the follow 
a glance at which will be more satisfactory than an attempt Ld 
te. ce 
ed in the Northwes 4 
made up of alternations of sandstones, olomites, come 
shells. The order of succession, lithological character and thie 
ness of the different members which are recognized in Iowa, DY 
be seen in the annexed table, arranged in an ascending 0 . 
. 
Name of Group, Lithological character. eae 
Potsdam Sandstone, - Pure silicious sandstone, 250-300 fee 
rer Magnesian Limestone, omite, ata 
Caleiferous Sandstone of N. Y. Rept.) 
Upper, or St. Peter's Limestone, Pure silicious sandstone, 80 
Alternation of slightly argilla- __ 
. ceous limestones and shells, 100-120 
with pure li 
Trenton, or Blue Limestone, 
