On Floating Ice in India. 431 
four to five* feet in diameter imbedded in a matrix which varies from a 
course sandstone to the very finest shale. 
‘In some places the matrix is a dark-green silt without any admix- 
ture of sand, but full of boulders of all sizes. Occasionally it is very 
fine in grain, and sometimes assumes a shaly structure. 
“The question naturally, indeed inevitably suggests itself, how these 
enormous blocks of stone, manifestly requiring a great force to abrade 
and transport them are found mixed with a sediment so fine that in any 
except a very sluggish current it must have been swept away, and could 
not have been deposited ? 
“Should any evidence hereafter accrue allowing the inference that 
these beds may have been formed in a lake on a high table-land, where 
the winter temperature was sufficiently low to admit of ice reaching the 
waters of the lake without melting, then an adequate explanation of the 
phenomenon may be given, as it resembles exactly the effects of the 
action of ground-ice which enabling boulders to be carried down by a 
sluggish current, would undoubtedly produce such an intermixture of 
large rounded masses of rock and of fine silt as is seen in the present 
case. 
“ Possibly a more minute examination of the boulders may reveal 
groovings and scratchings on their surfaces. The presence of these how- 
ever on the supposition of ground-ice having been the means of transport, 
should not by any means be looked for with certainty, and their much 
rounded condition? seems quite opposed to the idea of transport by true 
Glaciers. 
“Tt must be borne in mind that the temperature necessary to allow of 
Glaciers reaching the sea or a lake is very much lower than that at 
which ground-ice might be formed and carried down by rivers. While 
the existence of the former is determined by the mean temperature of 
the whole year, the latter depends on the lowest temperature of the 
winter season, and therefore may readily and does occur in countries 
whose mean temperature is comparatively high. 
“Thus in the northern part of the Black Sea at the present day, 
coast ice is always formed in winter, and this too in salt water ; the 
winter temperature there being equivalent to that of Central Norway, 
which is only a degree or two south of countries in which Glaciers 
come down to the sea level; while, on the other hand the summer 
* In areas which have subsequently been examined boulders having diameters three 
times as great have been met with.—V.B. 
+ This is not invariable as I have observed the deposit in some places to include sharply 
angular masses.— V.B. 
