792 GEOLOGY OF OHIO. 
Canadian highlands where such rock occurs, down the current of some 
stream which drained into the marshes of what is now the north end of 
the great Allegheny coal-field. 
A rounded bowlder of quartzite about five inches in diameter, was 
found buried in the block coal at the Foster shaft. Half of this has been 
presented to me by Mr. C. H. Andrews, of Youngstown. The material 
is a reddish, fine-grained congolmerate, metamorphosed into a dense 
quartzite. It was once smoothly rounded by attrition, and is evidently 
a bowlder from some stream bed or sea beach. No similar rock has up 
to the present time been found among the pebbles of the Drift or the Car- 
boniferous conglomerate, and it has apparantly been derived from a dif- 
ferent source. It resembles some of the metamorphic conglomerates of 
the Huronian in Canada and Lower Silurian of the Allegheny Belt. It 
is quite possible that 1t came from some parts.of the Blue Ridge, which, 
as we know, formed a line of shore east of the Allegheny coal-field, before 
the more modern folds of the Alleghenies were raised. <A careful compari- 
son of this specimen with the metamorphosed conglomerates of Canada and 
the Allegheny Belt will perhaps enable us to determine its place of origin. 
In the general submergence which resulted in the deposition of the sedi- 
ments which overlie the coal,the transportation of a block of foreign 
rock would seem to be a not improbable event, but as a matter of fact no 
such bowlders have yet been found in the shales or sandstones, and their 
occurence in the coal would lead to the conclusion that they were brought 
by the streams that drained ths country while the c-al was still forming. 
A larger bowlder of gray quartzite was found resting upon, partially im- 
bedded in Coal No. 6, at Zaleski, and is referred to on page seventy-eight 
of our Report of Progress for 1870. 
The chemical composition of Coal No. 1 may be seen by reference to 
the table of analyses at the close of this chapter. Its remarkable purity 
is only one of the good qualities which adapt it to the manufacture of 
iron. Its open-burning nature, which permits its use in the raw state, 
ig another and no less important excellence which it possesses. This 
latter quality is quite independent of its chemical composition, and 
seems to be due to its physical structure. Many coals which have a 
larger percentage of carbon and less bitumen—such as the Cumberland 
and Blossburg coals—are still conspicuously caking in character. The 
chief reason why the Brier Hill coal holds its form in the furnace is, as 
its seems to me, its laminated structure, layers of non-caking, cannel-like 
coal alternating with others which are bituminous and pitchy. Hence, 
its bitumen may be said to lie in cells, so that the mass does not melt 
down together, but splits along the planes of deposition, and burns like 
