XCH NOTES. 



in the text, they exercised great influence on the endeavours to improve 

 nautical astronomy, and especially the methods ot finding the longitude. It 

 is also very deserving of notice, that the capitulation of June 7, 1494, affords 

 the first example of a proposal to fix a meridian in a permanent manner by 

 marks graven in rocks, or by the erection of towers. It is commanded, " que 

 se haga alguna senal 6 torre" wherevei the dividing meridian, in its course 

 from pole to pole, whether in the eastern or the western hemisphere, inter- 

 sects an island or a continent. In continents, the raya was to be marked, at 

 proper intervals, by a series of such marks or towers j which would, indeed, 

 have been no small undertaking. 



(^ p. 280. It is a remarkable fact, that the earliest classical writer on 

 terrestrial magnetism, William Gilbert, who we cannot suppose to have had 

 any knowledge of Chinese literature, yet regards the mariner's compass as a 

 Chinese invention, which had been brought to Europe by Marco Polo.' 

 "Lla quidem pyxide nihil unquam humanis excogitatum artibus humano 

 generi profuisse magis, constat. Scientia nauticse pyxidulse traducta videtur 

 in Italiam per Paulum Venetum, qui circa annum mcclx. apud Chinas artem 

 pyxidis didicit" (Guilielmi Gilberti Colcestrensis, Medici Londinensis, de 

 Magnete Physiologia nova, Lond. 1600, p. 4). There are, however, no 

 grounds for the supposition that the compass was introduced by Marco Polo, 

 whose travels were from 1271 to 1295, and who therefore returned to Italy 

 after the mariner's compass had been spoken of by Guyot de Provins in his 

 poem, as well as by Jacques de Vitry and Dante, as a long known instrument. 

 Before Marco Polo set out on his travels in the middle of the 13th century, 

 Catalans and Basques already made use of the compass (see Raymond Lully, 

 in the treatise De Contemplatione, written in 1272). 



O p. 282. For the anecdote respecting Sebastian Cabot, see Biddle's 

 Memoirs of that celebrated navigator : a work written with a good historical 

 and critical spirit (p. 222). "We know," says Biddle, "with certainty 

 neither the date of the death nor the burying place of the great navigator 

 who gave to Great Britain almost an entire continent, and without whom (as 

 without Sir Walter Raleigh), the English language would perhaps not have 

 been spoken by many millions who now inhabit America." Respecting the 

 materials from which the variation-chart of Alonzo de Santa Cruz was com- 

 piled, as well as respecting the variation-compass, of which the construction 

 was already such as to permit altitudes of the sun to be taken at the same 

 time, see Navarrete, Noticia biografica del Cosmografo Alonso de Santa Cruz, 

 p. 3 8. The first variation-compass was constructed before 1525, by an 



