494 REPORT OF NATIONAL MUSEUM, 1904. 



the carving force of waters. The mountains themselves he thought to 

 have been elevated by successive but sudden earthquake movements 

 through and above the ocean; the water of which, as a consequence, 

 was propelled in gigantic billows and rushing sheets transversely across 

 the anticlinal ridges, scooping them out where weakest into the form 

 of terraced oval valleys. 



Slaty cleavage was looked upon as due not to movement, purely, but 

 to the action of haat waves traversing the rocks. In proof of this, 

 he cited his observations to the effect that, in gneisses lying in an 

 undisturbed horizontal position, the foliation is almost invariably coin- 

 cident with the stratification, the heat producing it having flowed 

 upward, invading stratum after stratum. Where granite occurs invad- 

 ing gneissic strata, the foliation, according to his views, is parallel to 

 the plane of outflowing heat. He thought to discover two general 

 laws: First, that the planes of foliation "are parallel to the waxes of 

 heat which have been transmitted through the strata, " and second, 

 "the foliation is parallel or approximately so to the cleavage, when 

 both occur in the same rock mass. 



A singular and, to the present writer, unaccountable discrepancy in 

 the work of Rogers lies in his almost completely ignoring the latest 

 glacial views as advocated by Agassiz and others. The fact that the 

 greater part of the work was completed and the manuscript prepared 

 prior to L848 can scarcely be considered a sufficient reason, since the 

 years 1851-1855 were devoted to its revision and bringing it up to date. 

 Moreover, his mention of the fact that the marine Pleistocene forma- 

 tion of Canada had been designated Laurentian clays by Desor (in 

 1850), shows that he was at least conversant with the literature of the 

 period; the fact that he had considered, if not fully comprehended, 

 Agassiz's views, is shown by a brief paragraph, in which he described 

 and figured drift stria? seen on an exposed surface of Umbral sand- 

 stone on the south side of the Wyoming Valley. These are described 

 as pointing up the slope toward the southwest, "as if produced by 

 fragmentary debris violently propelled against the sloping mountain 

 wall of the valley from the north." The presence of such ascending 

 stria?, both here and elsewhere, effectually refuted, according to his 

 conception of it, the glacial theory of their origin. Like Hitchcock, 

 he failed to conceive of other than local mountain glaciers of the Swiss 

 type. Without mentioning the name of Agassiz or other of his col- 

 laborators than that of Desor. he gave the following, even then anti- 

 quated matter, after a general discussion of the distribution of the 

 drift and the various phenomena accompanying it. For tin' earlier 

 drift, it should be noted, he offered no explanation whatever other 

 than implied in a reference to a period of repose which w " separated 

 the convulsed epochs of the earlier general and later local drift." 



A ready explanation of the origin of this newest Pleistocene deposit (i. e., that of 

 the Hudson and Lake Champlain districts) suggests itself when we consider the. 



