Editorial Comment. 55 
overflows, similar to what is common in the Keweenaw rocks, 
and, (4) it does not contain, except sparingly, fragments derived 
from the trappean series, and no more than can be referred to 
the slow accumulating action of waters in the production of a 
conglomerate from distant sources. These are severally set aside 
as invalid because based on incorrect observation. There is a 
surprising contrariety between the obsei'vations and conclusions 
of Mr. Wadsworth and those of Messrs. Irving and Chamber- 
lin. "In the Wall ravine, the eastern sandstone, instead of dip- 
ping beneath the Keweenaw beds as demanded by this hypothe- 
sis, shoots upward toward the zenith. * * * In the St. 
Louis ravine the beds are likewise turned skyward near the con- 
tact, and at a short distance away they dip at lower inclinations, 
away from the Keweenaw series; * * * in the region back 
from Ontonagon the eastern sandstone likewise dips away from 
the Keweenaw series near the contact. * * * and in none 
of these localities is there any approach to a conformity with the 
hypothesis of Credner and Wadsworth." Even at the ]> :;iiits 
which specifically were examined and described by Dr. Wads- 
worth, viz.: in the Douglass Houghton and the Hungarian 
ravines, "the eastern sandstone, instead of passing conformably 
beneath the trappean series with a like steady dip, is warped and 
angulated in a manner altogether inconsistent with the character 
of the Keweenaw series * * * and is discordant with the 
beds of the Keweenaw series." The bending downward of the 
eastern sandstone at the point of contact, in approximate con- 
formity with the overhanging Keweenaw beds, they regard as 
one of "the several phases of distortion that accompanies the 
coritact of these diverse formations." The sujDposed interstratifi- 
cation of the two formations is denied in toto, and the induration of 
the sandstone by heat is "no greater than at points distant from 
the contact;" and "if such induration were present it would be 
no proof of heat action." As to the presence of pebbles in the 
eastern sandstones, referable to the rocks of the Keweenaw se- 
ries, the authors aflirm that they find both acid and basic eruptives 
in that form, and that there is no other group of rocks known 
in the entire lake Superior region from which these pebbles 
could have been derived. It seems to us, however, that the ex- 
istence of these pebbles in the eastern sandstone allies it with the 
