386 pigafetta’s voyage round the world.
the earth: this axis revolves from eaft to weft, and in its revolution carries with it theplanets and all the ftars. Befides this there is an eighth fphere, the poles of whichare 23 0 33' * from the equinoctial line; the axis of this fphere turns from weft toeaft.
“ The circumference of the earth is fuppofed to be divided into three hundred andfixty degrees, and to each degree are affigned feventeen leagues and a half: the cir-cumference of the earth is confequently fix thoufand three hundred leagues. Theleague by land is three miles, the fea-league is fourf.
“ The ten circles of the armillary fphere, the fix larger of which have the famecentre as the earth, ferve to determine the climates and geographical fcite of places.The ecliptic /hews the courfe of the fun and planets. The two tropics point out thediftance to which the fun diverges from the equator, northward in fummer, and inwinter fouthward. The meridian, ever variable as it palfes through all the point of theequator, cutting it vertically, defignates the longitudes, and on this circle it is that thelatitudes are marked.” ,
After a defcription of the fyftem of Ptolemy , and after explaining every part of thearmillary fphere, the author teaches the manner of taking the height of the pole, bywhich means the latitude is found. He places the pole at o and the equator at go°
It is well known that at prefent we reckon from o to 90, beginning from the equatorand proceeding to the pole.
“ I. The polar ftar,” he fays, “ is not precifely on the point correfponding withthe axis of the earth, but like all the other ftars it revolves about this point. In orderto know the true pofition of the polar ftar with refpeft to the pole, that of the guards
* The declination of the ecliptic, which anfwers to the poles of the eighth fphere of oun author,is now 2^° 28^ 3®^*
f Suppofing the terreftrial globe under the equator to be fo divided that half its circumference fliouldconfift of land and half of water, and giving confequently to each league three miles and a half, we fhall have forthe circumference of the globe under the equator twenty-two thoufand and fifty miles ; a fum differingbut little from that which refults from giving fixty miles to each degree, which makes the circumferencetwenty-one thoufand fix hundred miles. Amoretti.
Here the Italian editor wholly miflakes his author, and fhews greater ignorance than could have beenfuppofed in a librarian having accefs to works on navigation, and digefting a treatife on this fcience. AHthat was meant by Pfgafetta in his obfervation that a league by land is but three miles, while a league atfea is four, is to admonifh the reader that in his computation of the circumference of the earth at fix thou-fand three hundred leagues, he means fea and not land leagues, for if the latter were taken the circum-ference would be eight thoufand four hundred. That this is the cafe is evidently clear from his obferviflgthat the fea league is of fuch length that feventeen and a half go to a degree, confequently feventy miles-Now the degree of longitude on the equator is 69,^ Englilh miles, and the circumference of the globe24,902 of thefe miles, which comes very nigh the computation of Pigafetta . Geographical miles wereutterly out of the queftion with him, (tliofe to which Amoretti adverts m computing 60 to a degree), Itis not however equally evident what mile he alludes to when he Hates the league to confilt of four ; thedegree meafures 67, T Vo the prefent miles of Milan, 68, T Va- of thofe of Tufcany, 6o, I 6 0 2 o of thofe °*
Venice, and 74, of thoTe of Rome. Eng. Tr.
£ This again is another error on the part of Amoretti, which attention to the text of the voyage mevery inftance where the latitudes are marked will clearly fhew ; it is alfo evidently a mif-ftatement fromthe tenor of the two inftrudlions which follow for finding the latitude, firft by an obfervation of the polarftar, and fecondly of the fun. Poffibly, though he fays he declined bewildering his brain in endeavouringto folve feme apparently incomprehenfible parts of this treatife, Amoretti did not defift from the attemptuntil it had become confiderably clouded ; at kaft thus much may fairly be conjedtured from the fta te *ments which have produced this and the preceding note. Eng. Tr.