924 . Comparative Studies upon the Glaciation, ete. (November, 
top of the ice, a fact due to the retardation by friction of its 
lower layers. The author had observed the gradual upward pas- 
sage of sand and stones in the Grindenwald glacier, and applied 
the same explanation to the broken shells and flint raised from 
the bed of the Irish sea to the top of Moel Tryfan, to Maccles- 
field and to Dublin mountains. 
The occurrence of stratified deposits in connection with un- 
doubted moraines was shown to be a common’ phenomenon, and 
instances of stratified moraines in Switzerland, Italy, America and 
Wales were given. The stratification is due to waters derived 
from the melting ice, and is not proof of submergence, 
It was held that, notwithstanding a general opinion to the con- 
i trary, there is no evidence in Great Britain of any marine sub- 
= mergence greater than about 450 feet. It was expected that an 
_. ice-sheet advancing across a sea should deposit shell Big 
in its terminal moraine. 
_ The broad principle was enunciated that wasecéie? in Great 
Britain marine shells occur in glacial deposits at high levels, it 
can be proved both by striæ and the transport of erratics that the 
ice advanced on to the land from out of the sea. The shells on 
: Three Rock mountain, near Dublin, and in North Wales and 
Macclesfield, all from the Irish sea, the shells in Cumberland — 
x transported from Solway Firth, those on the coast of Northum- 
_ berland brought out of the North sea, those at Airdree, in Scot- 
ia Caithness from Moray firth, were among examples adduced in 
roof of this: principle. The improbability of a great subme 
gence not leaving corresponding deposits in other parts of Eng- Ber 
land was dwelt upon. 
It was also held that there was insufficient evidence of more a 
an one advance in the ice-sheet, although halts occurred in e - 
retreat. The idea of successive elevations and submergence W! 
¢ vances and retreats of the ice was disputed, and the son 
eld that much of the supposed interglacial drift was due to su 
al water from the melting i we of 
> last portion of the paper discussed the distribution of 
gravels and clays south of the glacial area. Much a 
part of England was believed to have been aapos sl 
rhe drift deposits: in this area were shown t 
marine currents bovine icebergs during @ ; 
