To Thomas Jefferson from “A. Z.,” 25 July 1801
From “A. Z.”
U.S. July 25th. 1801.
Hypothesis 4th.
Having lately read your justly celebrated Notes on the State of Virginia, it occurred to my mind to account for the shells of fishes being on the mountains in Virginia and So. America in the following manner—
On the annexed figure, let A.B.C.D. have once been the figure of the Earth—the parts covered with red dots the land, the parts with black lines the water—by the motion of the Earth around it’s axis it flattened at the poles, and in time assumed the figure within the black line E.F.G.H. at which time, by means of the attraction of the opposite parts I.A.G. and K.C.G. they seperated, or broke asunder at the Pole, at G.—now, as the centre of gravity of one part might be in a direction to the centre of gravity of the other part, so would the parts in coming together be more or less turned over—so, that when the two parts came into contact, what was, before the fracture, at the bottom of the ocean, might, after the contact, become the top of a mountain—
I am aware the hypothesis may stand opposed to many and weighty objections from your great discernment—but have this consolation. that how many soever the shafts of ridicule winged at the hypothesis and it’s author, they will never hit the man—
A. Z.
RC (DLC); endorsed by TJ as received 6 Aug. and so recorded in SJL; with conjoined diagram on a separate page, picturing the Earth as a circle and using dots and lines as described above to depict a large sea reaching almost to the poles on the north and south and surrounded by land on the east and west, with a superimposed oval to show effects of flattening at the poles.
Hypothesis 4th: in Query VI of Notes on the State of Virginia, TJ discussed three suggested explanations for the presence of fossil seashells near the foot of North Mountain in Virginia and in the Andes. Those explanations were, first, a tremendous deluge; second, “some great convulsion of nature” by which the floor of the sea was thrust upward to a high elevation; and third, a suggestion by Voltaire that nature might create shell-like forms without the presence of marine life. In TJ’s opinion, “the three hypotheses are equally unsatisfactory; and we must be contented to acknowledge, that this great phænomenon is as yet unsolved.” The first edition of the Notes did not include the “convulsion of nature” possibility, which TJ introduced, along with the language referring to “three hypotheses,” in a substantial revision of his discussion of the subject in 1786 (, 31–3, 265–6; , 3:118–19).