Editorial Comment. 47 
had suggested running along the south side of the range, coinci- 
dent with the hne of contact. He regarded the eastern sand- 
stones as quite distinct from and more recent than those that are 
conformable above the Cupriferous series on the west slope of 
Keweenaw point. Dr. M. E. Wadswortli, in 1S79, made inde- 
pendent and thorough observations in the gorge below the falls 
■ of the Douglass Houghton ravine from which he came to the con- 
clusion that the beds of the eastern sandstone seen in this ravine 
pass below the trap and melaphyr beds of the Cuj^riferous series, 
although they also embrace beds of conglomerate and of diabase 
which are identical with some of the beds below which they run. 
He therefore announced that the "eastern sandstones "are of the 
same age as the Cupriferous series, and that at this point there is 
no unconformable position of one series of beds over the other. 
At the time of Mr. Irving's first examination (1880) he seems 
to have been in doubt whether the eastern sandstones, seen in 
the Douglass Houghton ravine were a part of the Keweenaw 
series or part of the eastern sandstone; yet in his published 
opinion' of the same year he vigorously attacks the conclusions 
of Mr. Wadsworth, and claims that the sandstone outcrops ex- 
amined by Wadsworth were a part of the Keweenaw series, and 
that a considerable interval which Wadsworth must have 
"bridged over in his imagination," entervenes between these 
beds and the true eastern sandstone strata further east which lie 
nearly horizontal. Dr. C. Rominger in 1883, considers the beds 
• described by Wadsworth " as making a part of the copper-i'ock 
group, although, considering their lithological character alone I 
would have united them with the eastern sandstone." He says 
that they "dip in conformity with the overlying diabase belts." 
This criticism Mr. Wadsworth answers by reaffirming his for- 
mer statement, and that by digging in the banks of the stream 
he actually traced the relations of this sandstone all the way 
from where it dipped in conformity with the Cupriferous series 
. down the ravine continuously to where the dip had subsided to 
five degrees. The pebbles and boulders that are referable to the 
Keweenaw eruptive rocks, seen in the sandstones and their asso- 
ciated conglomerates, appealed to by Irving to prove the prior 
' Monographs of the United States geological survey ; vol, v, p. 355, 
