In 1757 the humanist, scientist, and naval engineer Jorge Juan wrote his Compendio de navegación para el uso de los Cavalleros Guardias-Marinas. Por D. Jorge Juan, del Consejo de S.M. en su Junta de Comercio, Moneda, &c. Capitàn de Navio de la R. Armada y de la Compañía de Guardias Marinas, de la Real Sociedad de Londres, de la R. Acadèmia de Berlìn y Corr. de la de París.
The purpose of the work was to train the Cádiz midshipmen, and it became a compulsory textbook that was used for many years with very few modifications after the content on longitude was added. In including all the author's knowledge and innovative methods, it represented a major change to the way in which navigation textbooks were written.
The book was the first to come off the Company printing press. Jorge Juan had managed to equip the Company with its own press and avoid the books having to undergo prior censorship before being published. In addition, his texts were reviewed by experts rather than by members of the clergy.