Mo. 275.1 
77 
yards generally supply themselves from localities long used. The price 
paid for moulding sand is, in some places, 25 cents per bushel, so that 
a bank of it is of great value. It is composed of grains of quartz 
with some of feldspar, garnet, hornblende and magnetic oxide of iron. 
The water lines oblique to the strata, indicate the directions of the cur- 
rents that deposited the beds and strata of this material. Near our cities 
and large towns, where much sand is required for mortar, the sand and 
gravel beds of this formation are of great value, and their proprietors 
realize a large amount per acre for materials that are usually considered 
almost worthless. 
Clays. 
Both the blue and gray clays are plastic and are used in the manufac- 
ture of bricks, stone ware and coarse pottery. Both these clays contain 
carbonate of lime, and they may without impropriety, be called marly 
clays, and are well adapted for use on light soils. 
They will not only improve the texture of such soils, but they will 
supply some mineral substances which are necessary for the production 
of certain crops. They have already been used to some extent on such 
soils with advantage, and it is believed that they may be made more ex- 
tensively useful as a mineral manure. The uses of these clays for stone 
ware and pottery, are scarcely worth mentioning as statistical facts, as 
the amount of industry, capital and production is so limited. 
It is different with the brick manufacture, which employs a great 
amount of industry and capital. The gross number of bricks made in 
the counties under consideration, may be estimated at 42,900,000 per 
annum, with a value of $225,225, as the average sale prices at the kiln 
is about $5 to $5 .50 per thousand. 
Local Details of the Brick Manufacture. 
There are three brick yards in Dutchess county, that ought to have 
been mentioned in the geological report of last year, but were omitted 
through mistake. One is located near Break-neck Hill, and two others 
are in operation near the mouth of Fish Kill creek. They make about 
5,000,000 of bricks per annum. The estimated number of last year 
makes an aggregate of 17,000,000. 
