Washington, Novr. 28th. 1806
The Roof of the South wing of the Capitol having been completly boarded before the late heavy rain, it was sufficiently tight to throw a very large quantity of Water upon the Gutters which lie in the direction of, & over the Arch that surrounds the Area of the house. All the Water which fell between the Gutters & the external Walls was thus collected in a Body in the N.E & N.W, angles. These angles adjoining the North Wall have settled more than the rest of the Work, & on examining the course of the Water,—I fear that should we have soon severe frost, and the Water continue to collect in those places after rain, the consequence may be very dangerous. We cannot begin to cover with sheetiron untill better prepared, & I have therefore ventured to direct Mr Lenthall to shingle the exterior side of the Gutter so that the Water may be thrown into the Gutter itself & carried off by the spouthole. On the inner side of the Gutter no harm can be done.—The quantity of shingling is so small, compared with the rest of the roof, that it will be no material expense to take it up next Spring. In the mean time it shall be painted with Ashes, Land & Oil, a composition will render Wood incombustible. An experiment on a tolerably great Scale was made previously to the shingling of the Roof of the Capitol at Richmond. A small model of a house was made, which being covered with the pigment, was surrounded with wood, and a fire was made on the roof. The experiment succeeded compleatly, for the model remained unburnt. This gave Meriwether Jones occasion to remark, that Dr. Foushee, tired of his experiments on the Capitol roof, had burnt it in effigy.
I shall transmit to You tomorrow a copy of my annual report on the Public buildings for your review. The manner in which I Know your time to be occupied at present forbids my personally waiting upon You.—
I am with true respect Yours faithfully
B Henry Latrobe
DLC: Papers of Thomas Jefferson.