Part I. Report of progress in 1869, by J. S. Newberry, chief geologist. Part II. Report of progress in the second district, by E. B. Andrews, assist. geologist. Part III. Report on geology of Montgomery County, by Edward Orton, assist. geologist.

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the Canadian highlands. To the same source must be referred the sand,
as no silicious formation of any considerable extent occurs between
these deposits and the line of the great lakes. The sand and gravel have
a thickness of at least 100 feet in many instances. The deposits are
always distinctly stratified and exhibit many alternations of fine and
coarse materials that betoken considerable changes in the conditions of
their formation. They often show-especially in the beds that occupy
the lower levels of the county-beach-structure or marks of the action of
water that could only be impressed upon them while they lay at or near
the surface.
The sand and gravel are sometimes cemented into massive blocks by
the deposition of carbonate of lime from the spring-water that flows
over and through them. Reoourse was formerly had to these conglomerates for building-stone, but it was found that they were worthless for
such purposes, as they cannot withstand the action of frost.
The lost rocks-boulders, hard-head3, gray-heads, as they are frequently designated-constitute too important a feature of the geology of
the county to be omitted in this review. They are irregularly distributed
over the face of the country, sometimes thickly sown in belts of several miles in length and breadth, with tolerably definite boundaries, and
sometimes scattered singly at wide intervals. They occur through the
whole range of the Drift-beds, but are far more abundant in the uppermost portions than in any other. As in the case of the gravel, they are
all of northern origin, and by far the largest number have been brought
from beyond the great lakes. These boulders weigh not less than 160
pounds to the cubic foot, and the total weight of single blocks sometimes
exceeds 10 tons.
The economical values and the agricultural relations of the different
formations, will be treated separately. The various products that fall
under the head of economical values will be taken up in the following,order:
1. Building-Rock.
42. Brick, Draining-Tile and Pottery.
3. Firestone.
4. Lime.
5. Mineral Paint.
6. Gravel.
1. BUILDING ROCK.
Each of the formations above enumerated furnishes products in abundance for this important use.
The Blue Limestone affords, in numberless exposures, a building stone
that is accessible, easily quarried, even-bedded, of convenient thickness,
and very durable. It possesses, however, but little susceptibility of or