This cut follows an engraving (_Mag. of Amer. Hist._, iii. 178) after a photograph of one used by Champlain, which bears the Paris maker’s date of 1603. There is another cut of it in Weise’s _Discoveries of America_, p. 68. Having been lost by Champlain in Canada in 1613, it was ploughed up in 1867 (see Vol. IV. p. 124; also _Canadian Monthly_, xviii. 589). The small size of the circle used in the sea-instrument to make it conveniently serviceable, necessarily operated to make the ninety degrees of its quarter circle too small for accuracy in fractions. On land much larger circles were sometimes used; one was erected in London in 1594 of six feet radius. The early books on navigation and voyages frequently gave engravings of the astrolabe; as, for instance, in Pigafetta’s voyage (Magellan), and in the _Lichte der Zee-Vaert_ (Amsterdam, 1623), translated as _The Light of Navigation_ (Amsterdam, 1625). The treatise on navigation which became the most popular with the successors of Columbus was the work of Pedro de Medina (born about 1493), called the _Arte de navegar_, published in 1545 (reprinted in 1552 and 1561), of which there were versions in French (1554, and Lyons, 1569, with maps showing names on the coast of America for the first time), Italian (1555 with 1554, at end; _Court Catalogue_, no. 235), German (1576), and English (1591). (Harrisse, _Bibl. Amer. Vet._, no. 266.) Its principal rival was that of Martin Cortes, _Breve compendio de la sphera y de la arte de navegar_, published in 1551. In Columbus’ time there was no book of the sort, unless that of Raymond Lullius (1294) be considered such; and not till Enciso’s _Suma de geografia_ was printed, in 1519, had the new spirit instigated the making of these helpful and explanatory books. The _Suma de geografia_ is usually considered the first book printed in Spanish relating to America. Enciso, who had been practising law in Santo Domingo, was with Ojeda’s expedition to the mainland in 1509, and seems to have derived much from his varied experience; and he first noticed at a later day the different levels of the tides on the two sides of the isthmus. The book is rare; Rich in 1832 (no. 4) held it at £10 10_s._ (Cf. Harrisse, _Notes on Columbus_, 171; _Bibl. Amer. Vet._, nos. 97, 153, 272,—there were later editions in 1530 and 1546,—Sabin, vol. vi. no. 22,551, etc.; H. H. Bancroft, _Central America_, i. 329, 339; Carter-Brown, vol. i. no. 58, with a fac-simile of the title: _Cat. Hist. do Brazil, Bibl. Nac. do Rio de Janeiro_, no. 2.) Antonio Pigafetta in 1530 produced his _Trattato di navigazione_; but Medina and Cortes were the true beginners of the literature of seamanship. (Cf. Brevoort’s _Verrazano_, p. 116, and the list of such publications given in the _Davis Voyages_, p. 342, published by the Hakluyt Society, and the English list noted in Vol. III. p. 206, of the present _History_.) There is an examination of the state of navigation