2 FLEURIEU, Ch./ Testing chronometers of Berthoud 106


Description: Testing chronometers by Harrison's leading French rival

FLEURIEU, Charles Pierre Claret, Count d'Eveux de.
Voyage fait par ordre du Roi en 1768 et 1769, à différentes parties du monde, pour éprouver en mer les horloges marines inventées par M. Ferdinand Berthoud. Première[-seconde] partie, ...

Paris, Imprimerie Royale, 1773. 2 volumes. Large 4to (27 x 20.5 cm). Contemporary gold-tooled mottled calf, each volume with 2 green morocco spine labels, gold-tooled board edges, marbled endpapers. Each title-page with a different ornamental vignette by L. Luce that at first appear to be woodcut but are in fact assembled from large cast units designed to fit together. With many tables in text, 5 numbered folding engraved plates in volume 1 (4 maps of the Atlantic Ocean, the Canaries, the Azores, etc., and 1 plate with topographic diagrams); 1 folding engraved plate with geometrical figures illustrating the determination of latitude[!], and 5 folding letterpress tables (I-IV & II bis) in volume 2. Further with additional decorations built up from cast fleurons and 1 headpiece with what appears to be a true woodcut. [2], LXXIX, [1 blank], 803, [1 blank]; [2], 622, XL, [2 blank] pp.

First edition of an account by Charles Pierre Claret, Count Fleurieu (1738-1810), of the first voyage made to test the chronometers invented by his mentor, Ferdinand Berthoud (1727-1807), designated number 6 and number 8. They were developed to keep accurate time at sea in order to solve the problem of the determination of longitude, to make it possible for ships to easily determine their position. Berthoud closely followed the work of Harrison in England, who had already proven the efficacy of his chronometer no. 4 in 1761, but refused to allow Berthoud and others to examine it in 1763 because the British government had not paid him the promised £20,000 reward (he received the last part only in 1772). Count Fleurieu was a famous French statesman and scientist. As a scientist he was interested in the theoretical study of nautical sciences. Already as a young man he turned out to be a considerable talent, and gained admission to the Academy of Lyon. Guided by Berthoud, Fleurieu constructed several useful nautical instruments. During the voyages described in the present work, he tested Berthoud's chronometers as well as his own instruments on board the ship Isis, travelling to Cadiz, the Canaries, the Antilles, Santo Domingo, the Atlantic Ocean, Madera, and several other places. The results showed their success even beyond his own expectations. The present work is complete with the appendix dans lequel sont refermées diverses instructions sur la manière d'employer les horloges marines à la determination des longitudes ... Fleurieu also included some maps he had drawn himself during the voyage, determining position with the help of his own instruments and Berthoud's chronometer.
With an owner's inscription by an officer of the French Marine (I. J. St Bruq?) on both title-pages, the name struck through in the first volume. In very good condition, with only some minor, mostly marginal water stains at the beginning of volume 2. Folios e2 and e3 misbound at the end between 4I1 and 4I2.
Bibl. horlogère de Monsieur R.P. 196; Chadenat 2617; Gould, The marine chronometer (1960), p. 96 note; Tardy, p. 99.
  • Number: 1060791
  • Dealer: Speculum Orbis Nauticum