If the MS. in the Biblioteca Nazionale at Florence [_Cod. Magliabechiano Classe_ xi. _num._ 121], described by G. Uzielli in the _Bollettino della Società Geografica Italiana_, x. 1 (1873), 13-28 (“Ricerche intorno a Paolo dal Pozzo Toscanelli, ii. Della grandezza della terra secondo Paolo Toscanelli”), actually represents the work of Toscanelli, it is of great value in settling this point. The MS. is inscribed “Discorso di M^o Paolo Puteo Toscanelli sopra la cometa del 1456.” In it were found two papers: 1. A plain projection in rectangular form apparently for use in sketching a map. It is divided into spaces, each subdivided into five degrees, and numbers 36 spaces in length. It is believed by Sig. Uzielli that this is the form used in the map sent to Martinez. If this be so, the 26 spaces between Lisbon and Quinsai = 130°. 2. A list of the latitude and longitude of various localities, at the end of which is inscribed this table: Gradus continet .68 miliaria minus 3ª unius. Miliarum tria millia bracchia. Bracchium duos palmas. Palmus. 12. uncias. 7. filos. The Florentine mile of 3,000 braccia da terra contains, according to Sig. Uzielli, 1653.6^m. (as against 1481^m. to the Roman mile). Hence Toscanelli estimated a degree of the meridian at 111,927^m, or only 552^m. more than the mean adopted by Bessel and Bayer. Since, according to the letter, one space = 250 miles, and by the map one space = 5°, we have 50 miles to a degree, which would point to an estimate for a latitude of about 42°, allowing 67 2-3 miles to an equatorial degree. Lisbon was entered in the table of Alphonso at 41° N. (true lat. 38° 41’ N.) By this reckoning Quinsai would fall 124° west of Lisbon or 10° west of San Francisco. It does not appear that the Florence MS. can be traced directly to Toscanelli, but the probability is certainly strong that we have here some of the astronomer’s working papers, and that Ximenes did not deserve the rebuke administered by Humboldt for allowing 250 miles to a space, and assuming that a space contained five degrees. Certainly Humboldt’s use of 150 miles is unjustifiable, and his calculation of 52° as the angular distance between Lisbon and Quinsai, according to Toscanelli, is very much too small, whatever standard we take for the mile. If we follow Uzielli, the result obtained by Ruge (_Geschichte des Zeitalters der Entdeckungen_, p. 230), 104°, is also too small.[495] [Illustration: GAFFAREL’S MAP. From a map by Gaffarel, “L’Océan Atlantique et les restes de l’Atlantide,” in the _Revue de Géographie_, vi. p. 400, accompanying a paper by Gaffarel in the numbers for April-July, 1880, and showing such rocks and islets as have from time to time been reported as seen, or thought to have been seen, and which Gaffarel views as vestiges of the lost continent.]