From Peter Charles Varlé
Susquehanna Canal, 1 Feb. 1798. Having observed the ravages of yellow fever in Philadelphia in 1793 he developed a plan for countering the disease, which was favorably received by the people to whom he communicated it. Their attention to the subject lessened with the decline of the epidemic, but the return of the fever last year shows that the malady has not been eradicated. As this is a subject in which everyone concerned with the good of humanity will have an interest, he feels that he could do no better than to address himself to TJ as president of the American Philosophical Society. He is sending the explanation and plans of his idea, since the society makes itself acquainted with new inventions and will be able to appreciate the usefulness of his idea as well as correct any defects in it.
RC (PPAmP: Manuscript Communications, Medicine); 3 p.; in French; endorsed by the society as read on 20 Apr. 1798 and “Accompanying a project to prevent the Yellow fever from Visiting Philadelphia.” Enclosure not found, but see below.
Peter Charles Varlé learned civil engineering in his native France, worked under the supervision of the chief engineer of the island of Saint-Domingue from about the beginning of the French Revolution until 1793, then moved to the United States where he was employed on various canal projects. By 1798 he was superintendent of the Susquehanna Canal Company in Maryland. Beginning in the mid-1790s he published several maps, including one in 1808 of Frederick and Washington counties in Maryland that was the first county map in the United States to show land ownership as well as such features as roads, mills, taverns, and political boundaries. Varlé, who also submitted papers to the American Philosophical Society on other occasions, was active into the 1830s (Richard W. Stephenson, “Charles Varlé: Nineteenth Century Cartographer,” Proceedings of the American Congress on Surveying and Mapping: 32nd Annual Meeting [Washington, D.C., 1972], 189–98).
TJ probably did not deal personally with the contents of this letter, which he did not endorse or record in SJL. He attended a meeting of the society on 20 Apr. 1798 that authorized payment of two dollars in postage for Varlé’s communication, but the further disposition of the engineer’s proposal is unknown. A four-page undated paper by Varlé now in the society’s archives, “Reflexions Sur les Causes de la Fievre Jaune de Philadelphie, et Sur les Moyens d’en Preserver les habitants,” attributed yellow fever in Philadelphia to impure atmosphere resulting from industrial and commercial activities and a concentration of population, and suggested devices and measures for purifying the city’s air and water. Varlé also submitted a paper on yellow fever to the society in 1814, and it is uncertain whether the “Reflexions” formed part of his earlier or his later submission on that topic (MS in PPAmP: Manuscript Communications, written in French in Varlé’s hand, undated, with an endorsement, “Plan of a Lock C. Navigation 1796,” which evidently refers to a paper on locks for inland navigation that Varlé submitted to the society in 1807; APS description begins American Philosophical Society description ends , Proceedings, 22, pt. 3 , 270, 393–5, 443–4).