ciated with the iron ore in the ore mine of J. W. Leyde, in Hubbard township, is also not "Coal No. 2," as stated in the geological report, but a stratum lying sixty to eighty feet above the horizon of No. 2, probably the representative of No. 3. The same coal and ore are found on the lands of Jesse Hoagland, in Hickory township, Pennsylvania. Coal No. 2 is passed through in the air-shaft of Pierce's mine adjoining, eighty feet below the horizon of Hoagland's drift mine. Coal No. 1 was deposited, as I have stated, only in troughs or basins. When the carbonaceous matter which forms the coal had all accumulated, the center of the peat bog on the bottom of the swamp would be fully fifty feet thick; half way up the hill-side it would be twenty-five feet; while at its edges, or outcrops, not more than one foot would be accumulated. When the subsidence occurred and the sediments of the water settled over the coal marsh, the loosely matted vegetable material became compressed from fifty feet to four feet in the swamp, and from twenty-five to two feet half way up the hill, and from one foot to one inch at the edge. The strata forming over the coal vegetation in the swamp would bend as the coal became more and more compressed by the weight of the accumulating sediment, conforming to the bending of the coal, though in a less degree in ascending order. Hence when Coal No. 2 was deposited there was still an irregular, though a less irregular floor, waving up and down, as in the case of Coal No. 1. And this is what we find in practice, not only in the Brookfield Coal Company's mine, but in every mine in the Mahoning and Shenango valleys. These facts are proved by ocular demonstration in the air-shafts and hoisting-shafts of numerous mines. The hoistingshaft (or slope) is generally sunk in or near the swamp or low place in the coal, while the air-shaft is generally put down on the highest hills, and the two coals show the conformable character which I have stated. The cut on the following page illustrates the facts, and shows, also, the various strata and their frequent changes from rock to slate, etc.

In the deeper shafts of the valley there are three seams met with above the block coal; the upper two seldom rise to six inches in height, are often present only as a mere brace, and are frequently wanting altogether. They are doubtless the representatives of Coals Nos. 3 and 4, which, south of Mineral Ridge, rise to two and a half and three and a half feet.

The first twelve to sixteen feet of shale forming the cover of the block coal is generally a brown shale, hard and compact, making a firm and safe roof for the miners. The eight or ten inches next the coal is black and somewhat softer than the brown material, and is, particularly in the swamps, often filled with the impressions of fern leaves.

Above the brown shale there is a stratum of black and soft shale, of

varying thickness, upon which Coal No. 2 rests. Higher up the strata are very irregular, drill-holes seldom passing through material alike in thickness and character. In one hole there is sandstone in a homogeneous mass; in another the sandstone is met in several beds, with shales between them; and in the next there may be nothing but shale from top to bottom.

The shales are, however, the prevailing strata, many shafts, one hundred to one hundred and eighty feet deep, having few or no sandstone beds. The geologists, in locating a massive and persistent bed of sandstone above the coal, and separated from it by a few feet of shale, are misinformed as to the facts. A bed of sandstone is sometimes there, but it is, like all the sandstones, of irregular thickness and deposition. When present it generally cuts out Coal No. 2, and sometimes No. 1 also, forming the horsebacks of the mines.

Prof. Rogers, chief of the former Geological Survey of Pennsylvania, located this coal below the sub-conglomerate rock-the foundation-stone of the true Coal Measures-and hence called it a sub-carboniferous coal. Dr. Newberry, chief of the Ohio Geological Survey, has shown that its true place is above, not below, the Conglomerate rock, and that it is a true Coal Measure bed. Prof. Leslie, chief of the present Geological Survey of Pennsylvania, disputes Dr. Newberry's position, and reasserts that it is a sub-carboniferous coal. I have had repeated opportunities, both as a working miner and as mine inspector, to observe the position of this coal in many of the mines in the Shenango Valley of Pennsylvania, and in all of the mines of the Mahoning Valley of Ohio, and find it frequently capped with a Conglomerate rock, and still more frequently, especially in the swamps or troughs of the mines, not only below the horizon of the true Conglomerate, but also below the upper surface of the Waverly sandstone; and yet it is a true Coal Measure seam. The upper strata of the Waverly and the true Conglomerate also were deposited before the coal was deposited; the troughs or swamps in which the coal reposes below the horizon of the Conglomerate being, as has been shown, scooped or eroded out of a once comparatively level plain, anterior to the deposition of the coal vegetation. The pebbly sandstone sometimes forming the roof of the coal is not the equivalent of the pebbly sandstone underlying the coal, but a newer deposit of the Carboniferous age. In the Curtis Hill Mine, in Ohio, and in some of the mines in Pennsylvania, a conglomerate floor and a conglomerate roof are seen in the same working-place of the miner.

The accompanying cut shows the coal in the swamp below the upper surface of the Waverly sandstone. The coal ascending the hill on the

right rises over the top of the Waverly, and is seen to commence plunging downwards into an adjoining swamp. In the diagram there is no conglomerate present below the coal; but this is not an unusual circumstance. On the left side the coal does not rise more than half way on the hill till it is cut out by a white roof of fire-clay. The immediate cover of the coal in the swamp is a brown shale, a material uniformly forming the roof strata, except where a foreign material of fire-clay or sandstone appears. Three bore-holes are shown in the cut. The left hole, put down outside of the basin, strikes the Waverly-the "bottom rock" of the drillers-high above the coal in the swamp, and after passing into "bottom" a few feet, the hole is abandoned. The middle hole goes down

into the thick coal in the swamp, while the right hole taps the thin coal on the top of the arch which divides two swamps. Above the brown slate there is a bed of sandstone. This is not a persistent sandstone, but where present it sometimes comes down on top of the coal, and cuts into the seam, forming a horseback.

The Conglomerate overlying the coal and the sub-conglomerate forming the floor of the coal generally resemble each other in appearance, and are perhaps the same material, though of different ages. Dr. Newberry regards the upper member as the washings of the ancient beach. which bordered the coal marsh, and that it was deposited only on the extreme outcrop of the coal area. It is, however, not confined to the mines on the extreme outcrop of the coal area, but is found overlying the coal