STATE CONVENTION—GEOLOOT. 
20j 
ON THE RELATION OF THE WISCONSIN GEOLOG¬ 
ICAL SURVEY TO AGRICULTURE. 
BY PROF. I. A. LAPHAM, CHTBF GEOLOGIST. 
The law providing for a geological survey of the state of Wis¬ 
consin, includes also, and very properly, provision for some work 
for the special interest of agriculture; it being now generally 
known and admitted that these two subjects are so intimately re¬ 
lated that whatever is done to increase our knowledge of the local 
and special geology of any district, tends at the same time to pro- 
mote the interest of the farmer cultivating land in the same dis¬ 
trict. The underlying rocks are examined as to their chemical 
composition and surface arrangement or geographical extent—- 
they are the sources from whence is derived the very soil into 
which the farmer annually intrusts his seed. Their dip, order of 
succession, depth beneath the surface, their porous or impervious 
nature are investigated,—these are the data for deciding about 
Artesian or other wells, often the only resource for a permanent 
supply of water for farm purposes; and as the forests become re¬ 
duced in extent, the necessity for such wells will be gradually 
increased. The Drift phenomena, gleaned from a study of the 
loose materials covering and concealing the more solid rocks, left 
here by the glaciers of the Ice Period, the study of which is so 
interesting to the practical and speculative geologist,—they have 
been the means of diffusing and spreading the soil over the rocky 
surface, commingling and mixing the various clays, sands and 
ppbbles derived from the disintegration of the rocks, in such a 
banner as to render them best suited for the growth of vegetation. 
The mineral and other native resources are discovered and made 
known—they are the materials for various manufactories ; and 
their development creates a home market—the best of all mar¬ 
kets—for farm products, thus deciding the great question now So 
much agitated relating to cheap transportation, by avoiding the 
necessity of any transportation of these products. 
The barometrical measurements of the heights and depressions, 
