484 S. V. Wood,jun. — American and British Surface-Geology. 
Mr. Geikie insists on tke purely terrestrial origin of all this nn- 
stratified Glacial clay, and urges bis views in tke “ Great Ice Age ” 
with tke amplitude for wkick a work specially devoted to tke 
Glacial formation affords scope. It is irapossible to meet kis various 
contentions witkin tke limits of a paper like tkis ; but to insist, as 
he does, that rock-basins and great valleys of erosion have been 
excavated by tke treraendous agency which is exerted by tke 
combined vertical and horizontal force of glacier-ice thousands of 
feet thick moving over its bed, and at tke same time to contend that 
tkis ice can kave passed over fiuely-stratified sands, such as the 
Middle Glacial, pusking at tke same time under it a tkick moraine 
of clay brought from a distance, witkout disturbing the stratification 
in the slightest, does appear to me a most striking inconsistency. 
We are reminded by it of the steam-hammer which forges a 100- ton 
gun and cracks a nut witkout crusking the kernel ; but glacier-ice 
is not kept under the delicate control that a steam-hammer is. Not 
only is tke stratification undisturbed, but witkin very few feet of the 
junction of tkis undisturbed stratified sand with tke morainic clay 
tkere occurs in several places, both in tke East Suffolk cliff and in 
sections inland, a band of molluscan remains, mostly fragmentary, 
but containing intermixed with them an abundance of small papj j - 
raceous specimens of Anomi a ephippium, and of the valves of Baianus, 
sharp and unworn, both of wkick kave evidently fallen from objects 
floating in the sea. These small Anomice are so thin and tender that 
in tke fossil state in which we find them they exfoliate, and may be 
blown into fragments by a strong breatk ; and in tkeir living state 
they must have been very fragile. Are we to suppose that glacier- 
ice hundreds, nay, according to tke extreme glacialists, thousands 1 
of feet tkick passed over these sands, rolling its moraine as it pro- 
gressed, witkout eitker distorting the stratification of such sands or 
crusking the tender organisms witkin them wkick lie but very few 
feet from tke line of junction ? 
Tkis inconsistency becomes to my mind enkanced by Mr. Geikie’s 
contention that tke worn skells and shell fragments wkick occur in 
some of tke morainic clays, as, for instance, in the purple clay of 
Holderness, the ckalkless clay to tke north of it, and in the Lanca- 
skire clays, are due to the ploughing out of anterior (inter-Glacial) 
sea-beds, and the intermingling of tke ploughed-out slielly matter 
with the land-derived moraine material; for kow, if such tliings 
occurred, could the sea-bed formed of tke Middle Glacial sands to 
wkick I kave referred kave escaped destruction if tke glacier 
1 In objecting in my paper, “ On tbe Climate Controversy,” in this Magazine 
for September, 1876, tö the extreme thickness assigned to the ice of Britain during 
tbe Glacial period, I spoke of the existing Antarctic ice being at least 5000 feet 
thick. In this I was led away by the instances of bergs of tabular form having 
been met with in Southern seas which rose more than 500 feet or 600 feet above 
the sea, given by Dr. Croll in his work on “ Climate and Time.” From -the descrip- 
tion of the Southern bergs, liowever, given by the Challenger Expedition, I do not 
see how the Antarctic ice can at its sea termination much exceed 2000 feet, even if it 
reaches that. It seems probable, liowever, so far as Greenland and Spitzbergen 
disclose tbe case, that land-ice is of less thickness at the glacier terminations than 
where it lies in greater masses further inland. 
