I Cannot sufficiently welcome the two letters devoted to myself in the July Number of the Geological Magazine; and I only hope Mr. Harker and Mr. Deeley will continue to face the issues between us, and not be content, as others have been, with fulminating more or less testy protests, and then retiring from the field.

Mr. Deeley objects to my statement that the tendency of the most philosophical writers on geology is to go back from the scholastic formula of Uniformity enunciated by Lyell and Kamsay to more inductive reasoning. With the writings of Suess and Lapparent, of Spencer and of Prestwich, before me, all of them veterans of the first class, I cannot either understand or appreciate Mr. Deeley's protest.

In the abstract of the proceedings of the meeting, on November 8th, of the Geological Society of London, I notice that on the reading of Dr. G. M. Dawsou's “Notes on the occurrence of Mammoth-remainsinNorth-West America” the author cites the presence of Mammoth bones in a layer of clay resting on the “ground-ice” formation of the northern coast of Alaska and other areas.

I drew attention to this position of the Mammoth bones above the solid ice bothinNorth Siberia and Alaska, as proved by several explorers,inmy paper on “The True Horizon of the Mammoth” (GEOL. MAG., NO. 345, p. 107, March, 1893),inwhich I claimed for the Mammoth an existence long after the period assigned for its extinction by Sir Henry H. Howorth.

I see that Sir Henry, in the discussion of the paper, very naturally disagreed with the conclusion of Dr. Dawson as to the age of what is called by American geologists the “ground-ice” formation, and was of opinion “that this ice has accumulated since the beds were laid down in which the Mammoth-remains occur, and that the ice was not there when the Mammoth roamed about in the forests where he and his companions lived.”

Furthermore, he is reported to have said that “humus and soil cannot accumulate upon ice, except as a moraine,” both of which statements are controverted by the explorations of recent and competent observers who have examined these regions.

For some time I have had under observation the sections of drift exposed in the cuttings of the Seacombe branch of the Wirral Railway, and hope to describe them on some future occasion when the sections are nearer completion.

However, Mr. Mellard Keade has forestalled me in the description of one part of the sections, and professes to have foundinthem evidence of “ an ancient glacial shore.” What does he produce in favour of the statement?

After I had written the above dissertation and sent it for publication my attention was kindly drawn to a paper, dealing with the same subject, communicated by Mr. T. Mellard Reade, C.E., F.G.S., to the Liverpool Physical Society, and since republished in the May number of the GEOL. MAG. for this year (p. 203).

Having heard from my esteemed friend and colleague, Mr. J. W. Wetherell, that some years ago a brown crystalline substance had been found in a cave close to the sea, and situate between Porthcurnow and Porthchapel, I was impelled to make a search for the mineral. Last July I succeeded in finding a cave near Porthcurnow, the small opening into which was partially hidden by masses of fallen rock; here I found after a rough examination traces of the mineral for which I was looking.

General Mcmahon's paper in the GEOLOGICAL MAGAZINE for June attacks my conclusion that the Malvern biotite is formed from chlorite, but leaves my evidence untouched. Indeed, a large part of the article is occupied in discussing a theory which I do not hold. I have never said that the chlorite was converted into biotite by contact-action only. That there may be no further mistake, let me repeat that, in the Malvern rocks, chlorite is changed to biotite by contact-action plus dynamic deformation.

In the Geological Magazine for June and July of this year, I stated a new theory to account for the inequalities of the earth's surface, and, at the same time, offered a criticism of Mr. Eeade's theory, as epitomised by him in the May Number of the game Journal. in a short reply, contributed by Mr. Eeade to the September Number, he shows so clearly that he has totally misunderstood the physical reasoning upon which my theory is based, that some rejoinder is absolutely demanded.

In criticising my theory, he asks: “How then could the underlayers, by shrinking, exert such a huge pressure on the interior as to actually compress the materials of the earth into a smaller volume?” and, a few lines further on, he proposes that we should “work out the decrease of volume which would result from a given contraction of a shell of steel, 30 miles thick, acting on a sphere of the size and composition of our earth.”

Did I rely upon actual decrease of volume due to pressure, my theory would, of course, be absurdly untenable; but my reasoning is based upon the transference of material from beneath a surface of great pressure to below a surface upon which the pressure is much less. This I have so frequently reiteratedinmy paper that I could quote from almost any page; perhaps the following extract, taken from my first paper, will suffice: “The underlying material will be, so to speak, squeezed out, and this will cause a real transfer from under the sinking area to beneath the surrounding regions.”