I have received your Favour of the 13th Instant with several Packets of the Sheets. I have examined more of them, and hope to finish examining the rest before next Post, when I shall send you what Remarks have occur’d to me, towards furnishing your Errata.
I much like the Letters you propose to insert, as written from you to me; and am oblig’d to you for them, as they will adorn my Work. An Answer to one of them went in Tuesday’s Packet; but I am afraid ’tis written with too serious an Air. Mould it as you please. Some Observations on the others may soon follow. At present I confine myself, to what you seem most desirous of having immediately, my Remarks on the Translation of the Papers relating to the Powder Magazines. The Difficulty lies in the technical Terms used by Builders. To explain these, I must try to make a little Sketch of one of the Magazines. [The drawing on page 214 follows here in ms.]
aa is what in my Papers is called the Ridge of the House, and what appears you would call in French Sommet, ou faîte, and not corniche, as that would go along under the Eaves, as at bb.
The Shaded part from a to a, represents the bent Plate of Lead 22 Inches wide which covers the Ridge, from End to End, 11 Inches on each side, to prevent the Entrance of Rain where the Slates meet at top. This Plate of Lead, which in English we call a Coping, I suppose you would call Plaque or chaperon perhaps and not entablement. c is the Wall. d the Conductor [in margin: extending above the Ridge, but well united with the Plate of Lead at a].
Thus I imagine you would say at the Beginning of Section 2d of the Letter to Major Dawson, (but in better French than mine) “Que le batiment qui a une plaque [ou chaperon] de plomb le long du Sommet [ou faîte] peut être garanti, &c. communiquant avec cette plaque [ou chaperon]” &c. And at the End of the same Section; instead of le plomb qui couvre la corniche, say, la plaque du plomb qui couvre le sommet du comble. In the 3d Section, where mention is made of corniches revetues de plomb, perhaps it may be right instead of corniches to say, faîtes, ou sommets. And near the End, instead of entablements to say plaques, and instead of corniche, to say faîte, ou sommet. But as I am not Sure that I understand your Term arcboutans, I have endeavoured to give you the Form of these 4 Roofs, by a Sketch, wherein ab is the Ridge covered with Lead; ca and da are what we call the Hip-Joints, or Joinings of the Sloping Roof of the End with the sloping Roof of the Sides, which Joinings are also covered with Lead, to prevent the Entrance of Rain where the Slates meet. In this Form of Roof, the Proposal is, that the Iron Conductor should rise from the Wall e, as high as f, and thence extend its Arms to c and d. Thus the pointed Rod being erected at a would communicate with the Iron Conductor by means of the leaden Coping on the Hip Joints ac and ad. [The drawing on page 216 follows here in ms.]
In the Note after the Letter to Major Dawson, I would omit the Words à faire le frais du reste. The Idea of the Board being only this that they should be better justified in the Public Opinion, if they obtain’d the Sentiment of the Royal Society in favour of the Project, than if they acted upon the Advice of a single Person. As to the Expence, it was entirely in their own Power.
In the Report of the Committee near the Beginning of the second Paragraph for entablement de plomb, I suppose it should be plaque de plomb; and in the same line, for corniche, say faîte, or sommet du comble. Again in the 4th Paragraph, for entablement de plomb le long des goûtiêres, perhaps it might be, plaques de plomb le long les jointures du toit, jusques les goutieres, qui sont aussi de plomb, d’ou descendent, &c. I see my French must be abominable, but I hope you will understand it better than my English. Near the End of the 7th Paragraph, for corniche read sommet twice. In the 8th Parag. for grosseur read roideur, for corniche read sommet, and perhaps for l’entablement, read plaque; but I begin to think I do not rightly comprehend the meaning of your Word entablement; and that it may be proper in this Place. Towards the End of the 9th Paragraph for étendûë sur le comble, &c. read, étendûë sur le toit, [or, au travers du toit] avec la plaque de plomb du sommet, cette plaque de plomb étant absolument semblable a celle du sommet. In Paragraph 10. for corniche, read faîte, twice. All the rest seems to be right.
I suppose you have Copies of the Translations, you sent me, and that therefore I need not return them, as they would swell the Packet. I am, ever, with Love to Mrs. Dubourg, Your affectionate humble Servant