November 27

[On November 27, 1825, I wrote from Monticello to Mr. Lewis M. Wiss, responding to his request to review his naval engineering plans by outlining my own historical proposal for a dry lock-dock system designed to preserve warships high and dry under a roof. I recalled how, during my presidency, Congress was fiercely divided over the massive costs of maintaining an active navy, leading me to design a system fed by Washington's Tiber Creek to lift and store pristine hulls for decades without the ruinous expenses of decay or constant pumping. The letter captures me as an eighty-two-year-old man, plagued by ill health and just months away from death, still enthusiastically explaining the precise geometry and architectural inspirations of a decades-old failed pet project. My lifelong passion for scientific innovation and architectural engineering remained completely undiminished, even after the political world had long dismissed my ideas with ridicule.]

Disqualified by age and ill health from undertaking minute investigations, I find it will be easier for me to state to you my proposition of a lock-dock, for laying up vessels, high and dry, than to investigate yours. You will then judge for yourself whether any part of mine has anticipated any part of yours.

While I was at Washington, in the administration of the government, Congress was much divided in opinion on the subject of a navy, a part of them wishing to go extensively into preparation of a fleet, another part opposed to it, on the objection that the repairs and preservation of a ship, even idle in harbor, in ten or twelve years, amount to her original cost. It has been estimated in England, that if they could be sure of peace a dozen years it would be cheaper for them to burn their fleet, and build a new one when wanting, than to keep the old one in repair during that term. I learnt that, in Venice, there were then ships, lying on their original stocks, ready for launching at any moment, which had been so for eighty years, and were still in a state of perfect preservation; and that this was effected by disposing of them in docks pumped dry, and kept so by constant pumping. It occurred to me that this expense of constant pumping might be saved by combining a lock with the common wet dock, wherever there was a running stream of water, the bed of which, within a reasonable distance, was of a sufficient height above the high-water level of the harbor. This was the case at the navy-yard, on the eastern branch at Washington, the high-water line of which was seventy-eight feet lower than the ground on which the Capitol stands, and to which it was found that the water of the Tyber creek could be brought for watering the city. My proposition then was as follows: Let a b be the high-water level of the harbor, and the vessel to be laid up draw eighteen feet water. Make a chamber A twenty feet deep below high water and twenty feet high above it, as c d e f, and at the upper end make another chamber, B,

Proposed Lock

the bottom of which should be in the high-water level, and the tops twenty feet above that. g h is the water of the Tyber. When the vessel is to be introduced, open the gate at c b a. The tide water rises in the chamber A to the level b i, and floats the vessel in with it. Shut the gate c b d and open that of f i. The water of the Tyber fills both chambers to the level c f g, and the vessel floats into the chamber B; then opening both gates c b d and f i, the water flows out, and the vessel settles down on the stays previously prepared at the bottom i h to receive her. The gate at g h must of course be closed, and the water of the feeding stream be diverted elsewhere. The chamber B is to have a roof over it of the construction of that over the meal market at Paris, except that that is hemispherical, this semi-cylindrical. For this construction see Delenne's architecture, whose invention it was. The diameter of the dome of the meal market is considerably over one hundred feet.

It will be seen at once, that instead of making the chamber B of sufficient width and length for a single vessel only, it may be widened to whatever span the semi-circular framing of the roof can be trusted, and to whatever length you please, so as to admit two or more vessels in breadth, and as many in length as the localities render expedient.

I had a model of this lock-dock made and exhibited in the President's house, during the session of Congress at which it was proposed. But the advocates for a navy did not fancy it, and those opposed to the building of ships altogether, were equally indisposed to provide protection for them. Ridicule was also resorted to, the ordinary substitute for reason, when that fails, and the proposition was past over. I then thought and still think the measure wise, to have a proper number of vessels always ready to be launched, with nothing unfinished about them, except the planting their masts, which must of necessity be omitted, to be brought under a roof. Having no view in this proposition but to combine for the public a provision for defence, with economy in its preservation, I have thought no more of it since. And if any of my ideas anticipated yours, you are welcome to appropriate them to yourself, without objection on my part, and, with this assurance, I pray you to accept that of my best wishes and respects.