He tells us in one of his legends how to find the distance between two places represented on the globe, observing, "Si quorum voles locor[=u] distanti[=a] cognoscere ... tr[=a]sferto, hic tibi, [=q] libet particula [=i]tercepta millaria referet, Hisp: 18, Gal: 20, Germ: 15, Milia pass; 60, Stadia 500," from which it appears that he gives as the value of an equatorial degree 60 Italian miles or 500 stadia, equivalent to 18 Spanish miles, to 20 French miles, and to 15 German miles. Finding numerous errors in Ptolemy's geography of the Old World, he tells us that he undertook to correct these errors from the accounts of Marco Polo, whom he calls "M. Paulo Veneto," and from the accounts of Vartema, whom he calls "Ludovico, Rom Patricii." Between parallels 50 degrees and 60 degrees south latitude and meridians 60 degrees and 70 degrees east longitude is the inscription "Psitacorum regio a Lusitanis anno 1500 ad millia passum bis mille praetervectis, sic appellata quod psitacos elat inaudite magnitudinis, ut qui ternos cubitos aequent longitudine." "Region of parrots discovered by the Portuguese in 1500 who sailed along 2000 miles; so called because it has parrots of unheard-of size, measuring three cubits in length." America, he notes, is called New India, "America a multis hodie Noua India dicta." In the Antarctic region an inscription tells of the notion entertained by many geographers of his day and by some in an earlier day, that in addition to the four known parts of the world, Europe, Asia, Africa, and America, there is here a fifth part of large size stretching for a number of degrees from the pole, which region is called "terra Australe." Mercator undertook, in Chapter X of his 'Atlas,' to demonstrate that a large Antarctic continent must of necessity exist as a balance to the weight of the other four continents or parts of the world lying in the northern hemisphere.[275]