232 



logical Reports heretofore refeiTed to, as belonging to the lower coal ba- 

 sin, having a superincumbent mass at the centre of the basin of at least 

 300 feet. The sand rock on which this coal stratum rests, is estimated 

 by Mr. Hubbard's report of 1841, to be of an "aggregate thickness of 

 upwards of 300 feet." He further says in reference to it, "though here 

 classed as beneath the coal rocks, these sandstones are associated with 

 that series of rocks which are usually regarded as belonging to the car- 

 boniferous era." 



On consultation with Doctor Houghton, in 1845, and by his advice, 

 I decided on penetrating this rock directly below the shaft which had 

 been sunk through the coal bed. I accordingly prepared the nesessary 

 apparatus, and perforated the rock about 30 feet, passing through one 

 coal stratum of about 1 1 inches, and another of 3 inches. For the want 

 of suitable implements, and the impossibility of getting them made in 

 that then sequestered region, I was forced to suspend further drilling 

 into the rock, and it has not since been renewed. 



In 1850, I caused another shaft to be sunk, and the actual measure- 

 ment of the thickness of the coal bed at that point, was reported to me 

 to be 2 70-100 feet. 



In 1853, I first visited the out crop of the upper coal strata, at a 

 place called Grand Ledge, on the Grand River, in Eaton County. 

 Here I found the beds of coal imbedded in sandstone, about 12 feet 

 apart, and neither of them over 20 inches thick. The coal is of coarse 

 quality, and probably from its coarseness, and the thinness of the stra- 

 ta, it will not justify the expense of mining. Subsequently, in the 

 same year, I visited the out crop of the lower bed on Shiawassee Rivei', 

 and sunk six shafts, at different points, through it. I found the coal 

 bed so near the surface, that from atmospheric action or other causes, 

 the coal, which is about three feet thick, has been impoverishe<l ; so 

 that all the coal, except about fifteen inches at the bottom, has been 

 converted into bituminous .shale. The remaining portion is of great 

 purity, with the exception of a slight intermixture of iron pyrites. This 

 coal bed, to an extent of some 40 acres, appears to be on one uniform 

 level, and can never be available for profitable mining, until the dip in- 

 to the bowels of the earth shall have been found, as the expense of ex- 

 cavating the surface earth will doubtless be ei|ual to the value of the 

 coal. 



