Lecons de Navigation. Dulague 1814. This maritime book is titled “Lecons De Navigation” by Vincent Francois Dulague, the title means “Lessons in Navigation”, and the rest of the title page reads “Ancien Professeur d’Hydrographie, au College de Rouen, Membre de l’Academe des Sciences, Belles-Lettres et Arts de la meme Ville; A L’Usage de La Marine et des Ecoles D’Hydrographie. Septieme Edition Ornee de Huit Planches, Paris, Auguste Delalain, Imprimeur-Libraire, rue des Mathurins, Saint-Jacques, No, 5, 1814”. Translated, that means “Former Professor of Hydrography at the College of Rouen, Member of the Academy of Sciences, Belles-Lettres and Arts of the same city; For the Use of the Navy and Hydrography Schools. Seventh Edition, Decorated with Eight Plates”, and the book was published in Paris in 1814 by Auguste Delalain, Printer-bookseller, Mathurins Street, Saint-Jacques, No. 5. Hydrography is the science that measures and describes the physical features of bodies of water and the land areas adjacent to those bodies of water, and the book was a staple at European naval schools. Vincent Francois Dulague (1729 - 1805) was a Professor of Hydrography in Rouen who was well known for this book, as well as Principes de Navigation, ou Abrégé de la Théorie et de la Pratique du Pilotage (1787), which means "Principles of Navigation, or Summary of the Theory and Practice of Pilotage”, which was published in 1787. The book here was first published in 1768, and it was intended for the instruction of pilots and sailors. It is divided into five parts: it begins with the science of navigation, the second part is about astronomical observations essential for navigation, as well as the means to find latitude and longitude using the stars - the section ends with astronomical problems and solutions; the author devotes the third and fourth part of the book to how to steer a ship, the use of the compass, nautical charts, and the way to navigate by dead reckoning, and the last part is about how to figure out longitude by measuring the distances from the moon to the sun or stars, and it’s in the original French. (Dead reckoning is the process of calculating your position, especially at sea, by estimating the direction and distance you’ve traveled rather than by using landmarks or astronomical observations, or electronic gadgets, and they didn’t have electronic gadgets in those days.) The book has horizontal bands in gilt and gilt lettering on the spine, leather boards, blank endpapers, the half-title, a short list of prices for the book opposite the title page, then the title page with a vignette of a French warship, a leaf from the publisher, a two-page opinion from the editor (“Avis de L’Editeur”), a two-page Advertisement from the author for the sixth edition (Avertissement De L’Auteur Pour La Sixieme Edition”), a fourteen-page Table of Contents (“Table Des Matieres”), two pages for a Collection of Astronomical Tables (“Recuiel de Tables Astronomiques”), 358 pages of text, 95 pages of Astronomical tables, and seven fold-out plates at the rear, instead of the original eight. The book has heavy wear, with chips and faded lettering and faded gilt on the spine, wear along the edges of the spine and at the tips, scuffs on the boards, dampstains and brown spots, corner creases on some of the pages, the plates are rough - they have creases, browning, dampstains, some missing pieces, one has a split along a fold - one plate is missing at the rear, and actually a great background for principles of hydrography and navigation. The book is hard to find: there are only four listed on the rare book website we use and they range in price from $164 to $750. #164 #1607