a feeble one, in favor of the one opinion. The number of languages radically different, is a strong evidence in favor of the contrary one. There is an American by the name of Ledyard, he who was with Captain Cook on his last voyage, and wrote an account of that voyage, who has gone to St. Petersburg; from thence he was to go to Kamtschatka; to cross over thence to the northwest coast of America, and to penetrate through the main continent, to our side of it. He is a person of ingenuity and information. Unfortunately, he has too much imagination. However, if he escapes safely, he will give us new, curious, and useful information. I had a letter from him, dated last March, when he was about to leave St. Petersburg on his way to Kamtschatka. With respect to the inclination of the strata of rocks, I had observed them between the Blue Ridge and North Mountains in Virginia, to be parallel with the pole of the earth. I observed the same thing in most instances in the Alps, between Cette and Turin: but in returning along the precipices of the Apennines, where they hang over the Mediterranean, their direction was totally different and various: and you mention, that in our western country, they are horizontal. This variety proves they have not been formed by subsidence, as some writers of theories of the earth have pretended; for then they should always have been in circular strata, and concentric. It proves, too, that they have not been formed by the rotation of the earth on its axis, as might have been suspected, had all these strata been parallel with that axis. They may, indeed, have been thrown up by explosions, as Whitehurst supposes, or have been the effect of convulsions. But there can be no proof of the explosion, nor is it probable that convulsions have deformed every spot of the earth. It is now generally agreed that rock grows, and it seems that it grows in layers in every direction, as the branches of trees grow in all directions. Why seek further the solution of this phenomenon? Every thing in nature decays. If it were not reproduced then by growth, there would be a chasm. I remember you asked me in a former letter, whether the steam-mill in London was turned by the steam immediately, or by the intermediate agency of water raised by the steam. When I was in London, Boulton made a secret of his mill. Therefore, I was permitted to see it only superficially. I saw no water-wheels, and therefore supposed none. I answered you, accordingly, that there were none. But when I was at Nismes, I went to see the steam-mill there, and they showed it to me in all its parts. I saw that their steam raised water, and that this water turned a wheel. I expressed my doubts of the necessity of the inter-agency of water, and that the London mill was without it. But they supposed me mistaken; perhaps I was so: I have had no opportunity since of clearing up the doubt. *****