424 Prof. G. H. Stone—Stones of the Salt Range. 
movements and floating-ice, no test can be named whereby to dis- 
tinguish stones scratched in these ways from those of the glacier. 
In other words, in the present state of the argument, the scratching 
and facetting of the stones do not reveal their origin with certainty. 
Until proper tests are devised, we must rely on the general field 
evidence. Some progress can, however, be reported, for the facts 
certainly prove that the Salt Range specimens are not due to wind 
or water action. This narrows the field of future research some- 
what. It is desirable that observations of the stones involved in the 
other processes named should be studied as carefully as those of the 
glacier have been. 
It will be noted that the above stated conclusions are based solely 
on the nature of the markings on the specimens. These specimens 
are all the material I have for an inductive argument. The general 
argument in several ways will enable us to distinguish to some 
extent between the agencies above named as possible causes of the 
striation, but the matter is for the present lett to those who have 
studied the phenomena in the field. 
Four of the specimens described were not much, if in any way, 
worn by water. They were not, therefore, transported to their position 
in the midst of clay or sand by running water acting upon them under 
ordinary conditions. The writer has seen boulders four feet in 
diameter transported by the rush of water during a cloud-burst in 
Colorado, and left in the midst of mud and fine sand. If the 
boulder-bed were formed subaerially, and in a region of severe and 
sudden storms, the smaller boulders might possibly be accounted for 
as due to the rush of rapid waters over a soil deposited by rains of 
ordinary kind. Such a soil if subsequently eroded by the sea or 
a lake would become stratified and would contain the boulders 
previously strewn over the region, they being little, if at all, rounded 
during the erosion of the mud and soil. 
Still another method can be named for transporting the scratched 
stones and boulders to their present positions in the midst of clay 
or sand. A water-logged stratum of clay or shale is more likely to 
cause a landslip than any other kind of rock. Suppose such a mass 
of sedimentary clay to have been deposited over crystalline por- 
phyries previously shattered into boulders of decomposition. If 
afterwards the region is elevated so as to become part of a mountain 
range adjacent to the sea or a lake, subaerial erosion would begin to 
lay bare the underlying rocks, and the waves would form a zone of 
shingle along the beach. If, subsequently, landslips should occur 
along the mountain-sides, the clay would carry with it into the sea 
or lake many of the underlying boulders of decomposition and 
portions of the beach gravels. Many of the stones might be facetted 
and striated during the landslip, and we should now find them 
scattered through the clay or sand involved in the slip. And if this 
clay or sand were subsequently eroded by the lake or sea-waves, the 
larger stones would still be left in the midst of the fine material, 
being but little worn or polished during the process. 
The hypothesis of the stones and boulders found in the midst of 
