Ironhill, July 19th. 1805 near Elkton Maryland
Since my departure from Washington, I find by constant correspondence with Mr. Lenthall, that all the works at Washington are regularly going on.—A difficulty has however occurred in procuring the boards for the roof of the Capitol of heart pine 12 inches broad.—Mr. King the Timber merchant at Georgetown has declined engaging to supply them on any terms. I have therefore written to Mr. Lenthall and desired him, either to dispense with the requisite of the boards being entirely of heart, or to apply to Mr. Dublois or some other new England trader, for information as to the means and rate of obtaining a sufficient supply of White pine. The New England white pine is the timber employed by Palmer in the erection of all his bridges, and has a good reputation as to durability. Besides the situation in which it is to be used is perhaps as free from any cause of decay as any other can possibly be. We shall further have the advantage of being able to procure our boards of greater width,—at an average I suppose 15 inches, and the whole roof will be at least to Cent lighter. I should also think that the best white pine, in large quantity could be had from 16 to 20$ Thousand, while in Philadelphia, good yellow heart would cost from 28 to 30, & I suppose not much less in Washington.—I shall soon hear the result of his enquiries & communicate it to You.
I have a letter this day from Mifflin informing me that your Iron will go by the first Vessel to Richmond, & as his letter is dated the 12th. it is probably already on board.—I have also thought it right to secure as much Iron for covering the Capitol as possible, least this long draught should put us into the same predicament we were in with the President’s house, when no Slabs could possibly be had from the forges, for want of water in the Mill streams.—There is now at Washington Gutter Iron enough to cover the Offices of the Presidents house as soon as they are finished.
Mr. Lenthall in his last letter informs me, that the doors of the Offices at the East end do not fall in between the Columns. I am entirely at a loss to conceive how this can have happened, as in the plan I sent on, which agreed very nearly with Your original design I had been particularly attentive to this circumstance. The defect however will be hid whenever the Colonnade is put up.—By this days post I have sent to him sections in detail which will regulate the covering of the building so as to lay the platform 4 inches below the principal floor of the President’s house. I have allowed these 4 Inches, in order to give a proper drip for the Water which beats against the East Wall & Window & falls from the selle,—and which will now run upon the platform to escape clearly into the first Gutter, otherwise it will assuredly beat into the room. If you should however think it too much it may be lessened.
I regret also exceedingly a misunderstanding by which the North wall of the Offices has been carried up in the rough stone of the falls, instead of the rough freestone of the public Quarry at Acquia, a large quantity of which is on hand, and which stands the public in only 3. dols 75 cts. Ton. It was quarried last Year, in order to effect a better bargain with the proprietors of quarries, by a show of working the public Quarry: an attempt which perfectly recorded, & the expense of which was repaid in the diminished terms of the contracts. I am well convinced by experience that no stucco can stand on the North side of the building so near to the ground,—and that we had much better not attempt to put it on.
In looking over my books, I find in Professor Gilly’s great work on practical Architecture (Berlin 1800) a very compleat treatise on the De lorme roof. Every thing that has been done or written on the subject has been collected by him with German industry & correctness. He himself has constructed very many & large Domes & other roofs on this construction. I will send to you, as soon as I can possible make it, an extract of all he says on the subject.
In the course of my searches among the variety of books I possess, I have found a description of an artificial slate, (stone paper (Napier [gougiux]) invented by Professor Arfried Pace of Carlscrona in Sweden. Most respectable testimonials of its durability accompany the description,—which is not by the inventor but by Dr. Georgi of Petersburg,—an impartial witness. For as the inventor has refused to discover his composition, Georgi has subjected it to chemical analysis & finds it to consist of, 1., The common pulp used by paper makers in the composition of pasteboard. 2., Vitriol (sulphat of Iron I suppose) and 3., earth.—He gives a long process by which it can be made. He supposes that a species of petrifaction takes place in the composition. It may be sawed & planed, but soon dulls the tools. A Ship has been covered with it, which has made two Voyages to India, without any perceptible injury to the composition. It has been buried in the Earth, exposed to Frost, to Heat, to constant wet without damage. It is flexible & can be made in very large pieces. Its price is half the price of Tile. With so many wonderful qualities, it is extraordinary that it should since the Year 1785 not have come into more general use on the Europaean continent. And yet I do not find that its use even in Sweden has been very general.
In the course of a very short time I will do myself the favor to transmit all the information on the roof which I can give, and request your ideas on the subject. I find that both in France & Germany many deviations from Delorme’s manner have been advantageously practised.
With the truest respect I am Your faithful hble Servt
B Henry Latrobe
P.S. I have within a few days removed myself & family to this place where I enjoy perhaps the first wholesome air that is breathed NWestward of the Seacoast. The nearest post Office is at Elkton about 4 Miles distant. I am here in the Center of my operations on the lavel and if the woods were not in the way I could by turning round on the same spot discover Philadelphia, Wilmington, Newcastle, & Portpenn. I can now see at the same time the Deleware, and the Chesapeake.—
DLC: Papers of Thomas Jefferson.