IV.—On the Possibility of Changes in the Latitudes of Places on the Earth's Surface; being a Reply to Mr. Hill's Letter

Extract

I am grateful to Mr. Hill for noticing my former paper “On Possible Changes of Latitude on the Earth's Surface” in his letter, October, 1878, p. 479. I wish, however, that he had gone into the subject more in detail; in which case I, and perhaps others, would have felt more satisfied with his reply. He epitomizes my appeal to physicists by making me ask, “Assuming that a thin crust surrounds a fluid substratum, could then a deformation shift the crust over the nucleus?” And he replies that, Mr. G. Darwin having proved that the earth is “enormously stiff,” the discussion would be fruitless. But in this statement of my question and reply to it, he has omitted what seems to me the important proviso, based on Hopkins’ reasoning about the mode of cooling, that this fluid substratum is shallow, and encloses a rigid nucleus; and given no reply to my inquiry whether such a supposition might not afford the required rigidity.