Whittlesey.] 184 [November 18, 



In the language of the Report, " From Nashville, Holmes Co., to 

 the valley of the Kilbuck, the dip is eastward, and somewhat rapid. 

 From thence to the east line of Holmes County, the strata rise, then 

 dip again easiwardly into the valley of the Tuscarawas. From Dover 

 (on the Tuscarawas) to, and beyond the Tunnel, and to Carrollton, 

 the dip is westwardly, while from Hanover summit it is eastward to 

 the State line." No instance, local or general, is given in the Report 

 on the northeastern counties, of the precise direction, or the rate of 

 dip per mile. The process is very simple, being one of plain geom- 

 etry, and might easily have been applied. It would have been far 

 more satisfactory in the form of figures, than it is in such expressions 

 as "somewhat rapid." Elevations are given, but no application of 

 them in fixing the planes of dip. 



The quotation I have made embraces a summary of the supposed 

 discovery, which is dwelt upon at more length on pages 16 and 483. 

 Such a line of elevation exists on the Ohio River, but whether it is 

 due to a' corrugation of the Alleghany system, or to deposition, is an 

 open question. This line comes up from Burning Spring, in West 

 Virginia, crossing the river above Marietta, and extends northerly 

 through Noble County into Muskingum. Beyond this to the north I 

 find no traces of it. 



I propose to test the correctness of these conclusions of the Report 

 by utilizing its levels, together with such as I have taken or procured 

 during the past thirty-five years, applying the common mode of trian- 

 gulations, both local and general. By the use of a map of large 

 scale, these can easily be carried forward over the entire region, each 

 connected with the others. Small errors are unavoidable, but they 

 cannot seriously impair a protracted series of calculations. 



The inclination of a coal seam in one direction goes very little 

 towards fixing its true inclination in space. Local triangles determine 

 the local irregularities ; those of longer sides eliminate the local irreg- 

 ularities. Some of the results here reproduced were made public in 

 1856, and others in 1869, with maps, in the Memoirs of this Society. 

 No more important question can arise, connected with the geology of 

 this region. It involves a correct determination of the number of 

 coal seams, and their depth beneath the surface. It is capable in 

 theory of three solutions. 



First. — The beds may be regular and continuous, dipping from the 

 margin of the field on the north and west, towards the central line of 

 the basin beyond the Ohio River, south and east. In this event their 



