446 On the History o^ Fernel's Measure of a Degree. 



Leaf 2, page 2. " Cuivis gradui ambitus terree 68 milliaria, 

 95^ passus." 



Leaf 3, page 2. " Reperi passus 68096 qui milliaria sunt 

 Italica 68, cum passibus 96. Malui tamen hos passus, in 

 passus 95 cum uno quarto convertere, ne quaepiam fractio 

 foret in terras diametro praefigenda." 



Now let us ask what are 68*096 Italian miles? The Italian 

 mile was always used, under the idea that it was the old Roman 

 mile • from which in fact it differs little for our present pur- 

 pose, the latter being about 1614 yards, and the former 1628. 

 But not to take any point against Fernel's measure, let us 

 follow Dr. Bernard, who makes the statute mile to be 1056 

 paces, which would give 1667 yards to the mile of 1000 

 paces. This would give 64 1 English statute miles to Fernel's 

 degree, about Jive miles too little. And if, as is more pro- 

 bable, we take 1628 yards for Fernel's Italian mile, we find only 

 63 statute miles for his degree. The French toise is 2*1315 

 yards; so that Delambre makes Fernel's degree to be 69*12 

 miles. How he made the Italian mile longer* than the En- 

 glish statute mile, I have no idea. The confusion is older 

 than Delambre and Lalande, as appears by Montucla's first 

 edition. Riccioli gives a true account and so does Dr. Bernard. 

 Weidler (p. 341) omits all mention of the degree of the Cos- 

 ?notheoria f but says (without citing authority) that Fernel 

 undertook to measure a degree, which he finished in the year 

 1550. The copy from which I quote belonged to Montucla, 

 who has corrected errors in several places, but has taken no 

 notice of this, though I see from one of his marks that he 

 had read the page. Did Fernel measure another degree in 

 1 550 ? If so, what is the authority for it ? Why did Mon- 

 tucla, who is proved to have seen this very page of Weidler, 

 refer to the Cosmotheoria? And why is this second degree 

 mentioned only by Weidler? Perhaps some of your readers 

 may be able to clear up this point. 



Richard Norwood (Seaman's Practice, p. 41) being na- 

 turally desirous to get confirmation of his own degree (which 

 I cannot help thinking has been much underrated) first con- 

 trives to twist the Arabian degree into nearly the same as his 

 own ; and then allows Fernel's to come as near to it, but only 

 by representing (without authority) " the pace which he used 

 as being more than five of our English feet." Yet Norwood 

 himself, in the very first sentence of his own work, says, " It is 



* There is a Tuscan and Lombard mile in modern road-books, which is 

 a trifle longer than the English mile : but Delambre never could have mis- 

 taken this for the famous Italian mile, the universal standard of the middle 

 ages. 



