To Benjamin Franklin from ——— Beyer, 1 August 1784
From ——— Beyer4
ALS: American Philosophical Society
ce 1 Aout [1784]
Monsieur
Une indisposition m’ayant empeché de vaquer a mes affaires depuis 8 a 10 jours Je n’ai pas pû m’occuper du portefeuil5 ni de mon instrument6 etant obligé de garder la chambre mais jespere que les premiers Jours de la Semaine le tous poura âitre fini j’aurai lhonneur de vous en faire part aussitot que Sa Sera pret.
J’ai l’honneur d’etre avec un profond respet Monsieur votre tres humble Et tres obeissent Serviteur
Beyer
Notation: Beyer7
4. A German-born natural philosopher and inventor, residing in Paris, whose acquaintance with BF predated the present letter (the first in their extant correspondence) and continued until BF’s departure from France in July, 1785. In addition to conferring with BF about the inventions he discusses here, Beyer evidently also learned from him the art of building and installing lightning rods. In 1800 the French government commissioned him to set up lightning rods on public buildings and monuments in Paris, and to repair those already in place. Beyer’s lightning rods were distinguished by a point made of platinum and a pliable wire, covered with a layer of varnish, that aligned with the contours of the structure it protected. In 1804 Beyer devised a conductor that could be grounded or insulated at will, so that it not only offered protection from lightning; it also facilitated experiments with electricity: F.-J. Fétis, Biographie universelle des musiciens … (2nd. ed.; 8 vols., 1873–75; reprint, Brussels, 1963); Beyer, Aux Amateurs de physique, sur l’utilite des paratonnerres (Paris, 1806), frontispiece and pp. 2, 15–16n, 42–3n.
5. Beyer wrote that he had invented this tablet in response to BF’s desire to be able to write without being observed: Beyer, Aux Amateurs de physique, p. 56. In the Jour. de Paris of Nov. 18, 1785, Beyer advertised his “Portefeuille,” a portable writing device that made it possible to write in straight lines even in one’s “poche” or in the dark. It was useful for men of letters who wanted to be able to jot down their ideas discreetly at all times, whether at night or while walking and traveling. Moreover, the device featured a mechanism that moved the paper along during the process of writing, allowing the writing of up to 100 lines.
6. This was the glass-chord, a variation of the forte-piano, using glass bars instead of strings. It would not be ready until the following January, when Beyer presented a prototype to the Académie des sciences. After it received the academy’s approbation, BF obliged Beyer by giving the instrument its name: Beyer to BF, Jan. 17, and April 6, 1785 (APS); Beyer, Aux Amateurs de physique, p. 48.
7. On the verso of the sheet is an arithmetical calculation in BF’s hand.