Beschreibung:

DE BRAHM, WILLIAM GERARD]. The Atlantic Pilot. London: printed for the author, by T. Spilsbury, and sold by S. Leacroft 1772. 8vo, A-D4 1, original plain blue wrappers, rebacked, uncut, modern folding cloth case, edges chipped, leaf edges slightly frayed and browned, several fold breaks to the charts and table in spite of reinforcements with slight loss to a border of the first chart, 4-inch repaired tear to the second chart, the third chart cleanly torn from mount, the table marginally dampstained . 3 large folding charts: 1) "Hydrographical Map of the Atlantic Ocean...", showing the entire course of the Gulf Stream; 2) "The Ancient Tegesta, now Promontory of East Florida"; 3) "Chart of the South End of East Florida, and Martiers"; and one folding table with printed overflap, entitled "Loxodromy and Observations, from which the Map of the Atlantic Ocean is laid down." The German De Brahm (1717-c.1799), who had been Captain of Engineers under the Emperor Charles VI, became one of the most skilled and prolific mapmakers in the Southeastern colonies; he was Surveyor General of the Southern District of North America from 1765 to 1771. This very rare little pilots' guide was a "PIONEER ATTEMPT TO EXAMINE THE SOURCE AND NATURE OF THE GULF STREAM" (Cumming, British Maps of Colonial America , p. 52), based on observations that he carried out during an 18-week expedition in 1765 along the Florida coast and in the Gulf of Mexico, and during his crossing to England in 1771. De Brahm's investigations into the Gulf Stream thus predate Benjamin Franklin's work on the subject, the latter having at about the same time caused all known data on the current to be engraved on a commonly used chart of the Atlantic - but only later copies of Franklin's chart are known, dated 1786 and 1789. "[De Brahm's] studies, indeed, were carried further than his published work indicates, for one of the two unpublished De Brahm manuscripts now in the Harvard College Library is a continuation of the printed Atlantic Pilot , an extensive addition, with two manuscript charts, to his earlier investigations of the course and rate of flow of the Gulf Stream"--Lawrence Wroth, Some American Contributions to the Art of Navigation , Providence 1947, p. 29. Sabin 7324 (citing the title incorrectly); JCB (3) II:1821. Only one copy listed in ABPC since 1955; NUC cites one copy, at LC. Provenance : Accession number(?) 596 stencilled in red ink on title-page.