REPORT OF EXECUTIVE COMMITTEE. 
33 
has not been fully determined by analysis of the clay. It may 
be owing to a relative absence of iron, which gives the red 
color to ordinary brick, or to some peculiar changes in the- 
composition consequent upon heating in the kiln. In some 
localities it is doubtless due to the shaly character of the clay 7 
which seems to have been formed by a decay of the shales 
heretofore described. 
At Manitowoc, Newberg, Whitewater, and other places, these 
shaly clays are being used to a considerable extent and with 
success for the manufacture of potter’s ware; and, with proper 
encouragement, our own home potteries might be made to sup¬ 
ply the entire State with the coarser wares of this kind. 
Moreover, there is reason to believe that we have, in at least 
one locality, beds of Kaolin, or Porcelain Clay, of very superior 
quality, as will appear from the following communication from 
the Rev. J. Murrish, of Mazo Manie: 
Dr. J. W. Hoyt, 
Dear Sir :—The Kaolin of which I spoke the other day, and upon which 
1 promised to furnish a short article, is found near Grand Rapids, on the 
Wisconsin River. It was first noticed by Mr. John Road, and others, who 
were exploring that region for Mineral Veins, and specimens of it brought 
back and presented to me. The party afterwards sent a box of it to England 
to have it tested, and it was pronounced to be equal to the best English Clay. 
I cannot speak of the geological position and extent of this clay bed as 1 
could wish, not having visited it myself, but am assured by the parties who 
discovered it, that it is sufficient for manufacturing purposes; and from their 
description, I have no doubt the beds are very extensive. The importance of 
this discovery will appear, when we consider that Kaolin is found in but very 
few places in the United States; and nowhere, that I know of, in sufficient 
quantities, to justify the investment of capital necessary to manufacture it, 
but here. 
I hope to explore this part of the State myself sometime during the next 
summer, after which I shall be able to furnish you with more extended and 
important information on this discovery. John Murrish. 
Owen’s Geological Report also makes mention of beds of 
Kaolin at AVhitney’s Rapids, lower on the river. 
Water Lime , also known as Hydraulic Cement, occurs in 
numerous places in connection with the Lower Magnesian, the 
Trenton, and the Clinton and Niagara Groups of limestone. 
Prof. Daniels informs us he has found it, as a part of the Lower 
3 
