Prof. G. H. Stone— Stones of the Salt Range. 423. 
In several cases I have found in the fault-breccia stones that had 
been scratched, though none of them were facetted in so many 
planes as these. In the movements of faulted rocks we certainly 
have an agency capable of a steady motion and powerful enough to 
plane the hardest rocks. The facets of these specimens are not so 
smooth as ordinary slickensides on large masses of rock. Most of 
these scratches were made by graving tools not yet dulled by long 
friction. No. 5 may have been produced by a recent fault, the others 
must have been striated before deposition. The hypothesis that 
these stones were once a part of the fault-breecia would postulate 
faults occurring before the deposition of the boulder-bed, a portion of 
the breccia becoming in time exposed on the surface by the decay of 
the rock on each side of the fault, and the stones subsequently being 
carried by some means into the boulder-bed. There is much here 
_ that is unknown, yet every hypothesis that alleges a cause sufficient 
for the required work is entitled to a hearing and a fair decision 
according to the whole evidence. 
Eighth.—Were the markings caused by floating-ice? Mr. Oldham 
(loc. cit.) well sets forth the uncertainties regarding the work of ice- 
floes or bergs upon the stones contained within them. No one seems 
to have seen shore-ice or any other form of floating-ice facetting 
stones like the Salt Range specimens. The writer has visited several 
places on the coast of Maine where ice-floes had been driven ashore 
with such force as to pile up blocks of ice to the depth of ten to 
twenty feet. The shore was left strewn with stones and even large 
boulders four to six feet in diameter. The scratches on the stones 
were very irregular, in no way resembling those of the stones under 
discussion. The shore-ice during the rise and fall of the tides 
produces on the coast of Maine no such markings and planing. 
Bergs and thick floes would be less easily broken into blocks and 
might have greater power to facet stones than the shore-ice of Maine. 
In the present state of the argument floating-ice must be regarded 
as one of the possible agencies for facetting stones, yet one concerning 
which little is positively known. River-ice, especially at the time 
of the breaking of an ice gorge, is here included under the term 
floating-ice. 
The expansion of lake and river-ice produces scratches on the 
stones of the beach, but no such regular striation and facetting as 
that under consideration, and large stones driven swiftly along by 
water can be scratched, but not in a way like these. 
The only natural agencies that seem to be adequate to produce 
such straight scratches and such flat facets as those of the Salt Range 
stones that have occurred to me are glacier- and floating-ice, land- 
slips, and fault-movements; and concerning three of these agencies 
but little is known by direct observation. They must, however, 
be adequately considered before the theory of glacier-ice can be 
regarded as fully established, though the glacial hypothesis is not 
inconsistent with our supposing that part of the stones were 
formed in some other way than by glacier-ice. In the absence 
of direct observation of the stones involved in landslips, fault- 
