To Benjamin H. Latrobe
Washington Nov. 2. 1802.
The placing of a navy in a state of perfect preservation, so that at the beginning of a subsequent war it shall be as sound as at the end of the preceding one when laid up, and the lessening the expence of repairs, perpetually necessary while they lie in the water, are objects of the first importance to a nation which to a certain degree must be maritime. the dry docks of Europe, being below the level of tide water, are very expensive in their construction, & in the manner of keeping them clear of water, and are only practicable at all where they have high tides: insomuch that no nation has ever proposed to lay up their whole navy in dry docks. but if the dry dock were above the level of the tide water, and there be any means of raising the vessels up into them, and of covering the dock with a roof, thus withdrawn from the wet and sun, they would last as long as the interior timbers, doors & floors of a house. the vast command of running water, at this place, at different heights from 30. to 200 feet above the tide water, enables us to effect this desireable object by forming a lower bason, into which the tide water shall float the vessel & then have it’s gates closed, and adjoining to this, but 24 feet higher, an upper bason 175 feet wide, & 800 f. long (sufficient to contain 12. frigates) into which running water can be introduced from above, so that filling both basons (as in a lock) the vessel shall be raised up & floated into the upper one, & the water then being discharged leave her dry. over a bason, not wider than 175. feet, a roof can be thrown, in the manner of that of the Halle au blé at Paris, which needing no underworks to support it, will permit the bason to be entirely open & free for the movement of the vessels. I mean to propose the construction of one of these to the National legislature, convinced it will be a work of no great cost, that it will save us great annual expence, & be an encouragement to prepare in peace the vessels we shall need in war, when we find they can be kept in a state of perfect preservation & without expence.
The first thing to be done is to chuse from which of the streams we will derive our water for the lock. these are the Eastern branch, Tyber, Rock-creek, & the Potomak itself. then to trace the canal, draw plans of that and of the two basons, and calculate the expence of the whole, that we may lead the legislature to no expence in the execution of which they shall not be apprised in the beginning. for this I ask your aid, which will require your coming here. some surveys and levellings1 have been already made by mr N. King, a very accurate man in that line, and who will assist in any thing you desire, and execute on the ground any tracings you may so direct, unless you prefer doing them yourself. it is very material too that this should be done immediately, as we have little more than 4. weeks to the meeting of the legislature, and there will then be but 3. weeks for them to consider and decide before the day arrives (Jan. 1.) at which alone any number of labourers can be hired here. should that pass, either the work must be over for a year, or be executed by day labourers at double expence. I propose that such a force shall be provided as to compleat the work in one year. if this succeeds, as it will recieve all our present ships, the next work will be a second one, to build and lay up additional ships. on the subject of your superintending the execution of the work it would be premature to say any thing till the legislature shall have declared their will. be so good as to let me hear from you immediately, if you cannot come as soon as you can write. Accept my best wishes and respects.
PrC (DLC); at foot of first page: “Mr. Latrobe.”
HALLE AU BLÉ: as designed by Nicolas Le Camus de Mézières, the Paris grain market, the Halle aux Bleds, was a circular building surrounding a courtyard that stood open to the sky. Several years after the completion of the building in 1767, architects Jacques Guillaume Legrand and Jacques Molinos, using methods developed by the Renaissance builder Philibert Delorme, constructed a great dome of wooden ribs and tall windows to turn the courtyard into a vast interior rotunda, protected from the elements but filled with light. After the dome was finished in 1782, municipal authorities used the Halle aux Bleds as the site of significant public ceremonies, and the building was an attraction for visitors to Paris intrigued by the rotunda’s design and carpentry. In 1786, TJ, seeking ideas for the design of a public market for Richmond, decided to visit “the noble dome of the Halle aux bleds,” which he called a “wonderful piece of architecture.” As memorialized in his famous “Head and Heart” letter, it was on an excursion to see the great dome with John Trumbull that TJ first met Maria Cosway. The dome burned and collapsed in 1802 and was rebuilt beginning in 1809 using iron ribs rather than wooden joinery (Harold C. Rice, Jr., Thomas Jefferson’s Paris [Princeton, 1976], 6, 18–21; Vol. 10:xxix, facing 434, 444–5).
OVER FOR A YEAR: slaves hired out by their masters on an annual basis made up a large proportion of the labor force on big construction projects in and around Washington (Robert J. Kapsch, The Potomac Canal: George Washington and the Waterway West [Morgantown, W.Va., 2007], 82, 106, 213; Letitia W. Brown, “Residence Patterns of Negroes in the District of Columbia, 1800–1860,” RCHS description begins Records of the Columbia Historical Society, 1895–1989 description ends , 69–70 [1969–70], 68; Cora Bacon-Foster, “Early Chapters in the Development of the Potomac Route to the West,” same, 15 , 159, 193; Bob Arnebeck, Through a Fiery Trial: Building Washington, 1790–1800 [Lanham, Md., 1991], 205–6).
1. Preceding two words interlined.