On the ParalleHsrii of Ooal-Seains. 267 



The soft, pattering sound nnide by some species of Acridimn and Ca- 

 Inptenus during flight, is probably due simply to the beating of the air 

 by the wings, as it does not appear to be confined to sex, the males 

 only of grasshoppers being furnished with apparatus for producing 

 notes. 



On the Parallelism of Coal-Seams. By J. S. Newberry. [From the 

 Am. Journal of Science and Arts, April, 1874, 



• In the first volume of the final report of the Geological Survey of 

 Oliio, Professor E. B. Andrews advances a theory in regard to the 

 successive deposition of coal strata which, if permitted to go unques- 

 tioned, might seem to commit the other members of the geological 

 corps to its approval, whereas, as a matter of fact. Professor Andrews 

 stands quite alone in its support. Very briefly, his theory is this: 

 1st, That coal-seams have accumulated iu marshes along the sea shore, 

 and, therefore, at or near the water-level ; 2d, That the subsidences 

 by Avhich several coal-seams w'ere successively formed and buried were 

 continental and general; and, 3d, That the coal-beds, from their 

 mode of formation, must necessarily be parallel to each other, and, 

 hence, a discrepancy iu the distances from a. given coal-seam, taken as 

 a base, to two or more outcrops of what might be considered the same 

 seam, is a proof that the coal of these outcrops belongs to different 

 seams. Professor Andrews also says that he has never seen a coal- 

 seam dividing into two or more distinct seams, or two seams approach- 

 ing each other. 



While not questioning the accuracy of Professor Andrew's' report of 

 his own pbservations, I am compelled to say that the facts observed by 

 myself are not only discordant "with his, but are such as seem to me 

 to be incompatible with his theory. In the northern half of the Ohio 

 coal-field, numerous instances of the approach and divergence of 

 plainly continuous coal-seams might be cited. For example : On one 

 tract of coal land in Hubbard, Trumbull county, the distance which 

 separates , the first from the second coal-seam, varies from 44 to 100 

 feet; coal No. 1 showing conspicuous waves or folds, while No. 2 is 

 nearly horizontal (M. C. Read). At Fredericksburg, Wayne county, 

 the distance between the two limestone coals, Nos. 3 and 4, is only 

 20 feet, but on tracing these seams down the valley of the Killbuck, 

 they ai-e seen to gradually diverge, until, at Millersburg, they are 



