Benjamin Franklin Papers

From Benjamin Franklin to Samuel Rhoads, 10 February 1771

To Samuel Rhoads

ALS: Historical Society of Pennsylvania

London, Feb. 10. 1771.

Dear Friend,

I received your kind Favour of Nov. 9.9 and am glad to hear of the Welfare of you and yours.

Mentioning to a Friend of mine, Mr. Wooller, an Engineer,1 your Idea of Paint and Sand, to make Roofs durable and safer from Fire (which I hope you will try, as I think it very likely to succeed) he communicated to me an Account of a new Method of Covering, in the North, that is in some respects similar, may be as durable, but in my Opinion not so safe. Perhaps it may be of Use for Summer-Houses, Barns, Outhouses, or Buildings where no Fire comes (and therefore I send you the Account enclos’d); but I think I should not care to trust it in a Dwelling-House, in a Town, unless the under Side of the Boards was lathed and plaistered between the Rafters, which would add to the Expence: For tho’ the Outside, hardened by the Air, and paved, as it were, by the Sand, Shells, &c. might not readily take fire, the Tar coming thro’ the Seams or Craiks of the Boards might be readily inflamed by a Candle from the Inside, placed carelessly by Servants in a Garret.

The Flatness of this Roof, as well as of those with Copper, lessens a good deal the Areas to be covered, and of course the Expence.

I am glad to hear that you have good Workmen in the Stucco Way, and that it is likely to take place of Wainscot.

In some of the Paris Buildings the Floors are thus formed. The Joists are large and square, and laid with two of their Corners up and down, whereby their sloping Sides afford Butments for intermediate Arches of Brick. Over the whole is laid an Inch or two of Loom,2 and on that the Tiles of the Floor, which are often sixsquare, and painted. The lower Corner of the Joints is cut off enough to admit of nailing to them the Laths that are to hold the Plaister of the Cieling of the Room beneath. Where there is any Apprehension of Walls spreading by the Weight of such Floor, they are prevented by Bars of Iron, with external SS. This kind of Floor seems safe from Fire: For the Joists in Contact with the Bricks above, and shielded by the Plaister Cieling below, are not very likely to kindle and burn. It likewise prevents in a great degree the Noise of what is doing overhead offending those below. But it is heavy, takes up more Room, requires great Strength of Timber and is I suppose more expensive than Boards. I apprehend those Arches are not generally us’d; but the Tiles are more commonly laid upon rough Boards, and the Joints clos’d with fine Mortar or some kind of Cement.

Plaster Floors are of late coming again into Use here. I know not whether we have the proper Materials in our Province; but I have been told there are Quarries of the kind in Nova Scotia near navigable Water. I send you however an Account of the Method of laying such Floors. Also some Specimens of a new-discover’d Limestone for Mortar that sets under Water, with a Written Account of the Method of managing it. All from my Friend the ingenious Mr. Wooller.

Remember me respectfully and affectionately to Mrs. Rhoads and my dear old Friend Mrs. Paschal. With sincere Esteem, I am, dear Friend Yours most affectionately

B Franklin

I send you also a Pamphlet on the Subject of securing Houses from Fire, tho’ the Method is perhaps impracticable with us.3

Saml Rhoads, Esqr

[Note numbering follows the Franklin Papers source.]

9Not found, but presumably an answer to BF’s letter above, XVII, 181–3.

1For John Wooler see above, XVII, 182 n.

2Presumably a slip for “loam,” although ordinary loam seems an unsatisfactory base for tiles. Perhaps BF had in mind some variety resembling casting-loam.

3The pamphlet may well have been L. Dutens’ translation of Félix François d’Espie, The Manner of Securing All Sorts of Buildings from Fire. Or a Treatise upon the Construction of Arches Made with Bricks and Plaister, Called Flat-Arches, and of a Roof without Timber Called a Bricked-Roof... (London, n.d.). If this was in fact what BF sent, he had good reason to question the applicability of the method in America.

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