James D. Hardy— Glacial Submergence. 277 
Owing to the fact that the addition of fresh silica often destroys 
all traces of the growth-stages of a flint, very little information can 
be obtained when the process is complete and the nodule a mere 
solid mass of flint. Fortunately there are innumerable cases to be 
found in every stage of development, and those who care to look 
can find them in most districts of the 8.E. of England where the 
Upper Chalk exists. The absence of flint in our lower beds* would 
of course be explained by the assumption that only half the beds were 
above the sea-level when the process of segregation was going on. 
I may, in conclusion, reduce my suggestions to the following pro- 
positions :— 
1st. That Flint in the form now found in the Chalk was deposited 
subsequent to its upheaval above sea-level. 
2nd. That whilst the large quantity of siliceous sponge spicules 
present must have had a considerable share in the formation of the 
nodular and perhaps the tabular flints, yet quite as frequently various 
other hard substances and even empty spaces assisted. 
3rd. Chalk flints grew after the manner of crystals [ or concretions? | 
and were regulated by similar laws. 
TUNBRIDGE WELLS. 
XI.—Anotuer View oF THE SUBMERGENCE OF THE BritisH ISLEs 
DURING THE GLACIAL PERIOD. 
By James D. Harpy. 
QUITE agree with the submergence of the British Isles during 
the last or any Glacial period ; but I totally disagree with the 
theory that there has been any such depression of the land as is 
generally put forward by geologists. Where is the evidence of such 
depression? Certainly not since Pliocene times, unless the whole 
of Great Britain sunk and rose simultaneously like the parallel 
motion of a beam engine. Such a motion would imply not only a 
surface movement, but also a sinking of all underlying strata. How 
such a theory ever held for a time is a puzzle to me, excepting the 
absolute necessity of finding some reason for the sand and shell 
deposits up to 1500 feet O.D. That the whole of England and at least 
the greater part of Scotland was covered with water there is evidence 
enough, and that Britain was not covered with an Ice-cap there is 
also evidence, if one will look at it free of all old book theories. 
Geologists—like other specialists—follow their bell-wethers, first in 
one direction, then in another, and are rarely able to bring other 
knowledge to bear on their arguments, as I have found when arguing 
on this depression theory with them. 
1 Mr. David Forbes, F.R.S., pointed out, many years ago, that the Hard Chalk 
and Grey Chalk really contained an equal quantity of silica as the Upper Chalk with 
flints, but it had not segregated out into flints in the former as in the latter formation. 
An excellent account of the Chalk formation and of the Flints and their probable mode 
of origin will be found in the Geology of England and Wales by Horace B. Wood- 
ward, F.G.S. (1887) pp. 397-401. See also paper on Banded Flints by Dr. S. P. 
Woodward (Gzon, Mae. 1864, pp. 145-149, Plates VII. & VIAI.), and the Isle of 
Thanet and its Continuity of the Flint Floorings by F. A. Bedwell, M.A., F.R.M.S. 
(Gzou. Mac. 1874, pp. 17-22, and Proc. Geol. Assoc. 1873, vol. iii. pp. 217-238, 
pl. iv.).—Hpir. Grou. Mag. 
