his errors in latitude are not so important; and though the latitude he assigns to particular places is incorrect, yet the length of the globe, according to him, or the distance from the extreme points north and south, then known, is not far from the truth.  Thus the latitude of Thule, according to Ptolemy, is 64 degrees north, and the parallel through the cinnamon country 16 deg. 24’ south, that is, 80 deg. 24’ on the whole, a difference from the truth of not more than six or seven degrees.  It is remarked by D’Anville, and Dr. Vincent coincides in the justice of the remark, that the grandest mistake in the geography of Ptolemy has led to the greatest discovery of modern times.  Strabo had affirmed, that nothing obstructed the passage from Spain to India by a westerly course, but the immensity of the Atlantic ocean; but, according to Ptolemy’s errors in longitude, this ocean was lessened by sixty degrees; and as all the Portuguese navigators were acquainted with his work, as soon as it was resolved to attempt a passage to India, the difficulty was, in their idea, lessened by sixty degrees; and when Columbus sailed from Spain, he calculated on sixty degrees less than the real distance from that country to India.  Thus, to repeat the observation of D’Anville, the greatest of his errors proved eventually the efficient cause of the greatest discovery of the moderns.

Beside the peculiar merit of Ptolemy, which was perceived and acknowledged as soon as his work appeared, he possesses another excellence, which, as far as we know, was first pointed out and dwelt upon by Dr. Vincent.  According to him, Ptolemy, in his description of India, serves as the point of connection between the Macedonian orthography and the Sanscrit, dispersing light on both sides, and showing himself like a luminary in the centre.  He seems indeed to have obtained the native appellations of the places in India, in a wonderful manner; and thus, by recording names which cannot be mistaken, he affords the means of ascertaining the country, even though he gives no particulars regarding it.  We have applied this remark to India exclusively, but it might be extended to almost all the names of places that occur in Ptolemy, though, as respects India, his obtaining the native appellations is more striking and useful.

Having offered these general remarks on the excellencies and errors of Ptolemy, we shall next proceed to give a short and rapid sketch of his geographical knowledge respecting Europe, Asia, and Africa.  On the north-east of Europe he gives an accurate description of the course of the Wolga; and further to the south, he lays down the course of the Tanais, much nearer what it really is than the course assigned it by Strabo.  He seems to have been acquainted with the southern shores of the Baltic from the western Dwina, or the Vistula, to the Cimbric Chersonesus:  he also describes part of the present Livonia.  The Chersonesus, however, he stretches two degrees too far to the north, and also gives it too great a bend to the east.  He applies the name of Thule to a country situated to the north-east of Britain; if his usual error in longitude is rectified, the position he assigns Thule would correspond with that of Norway.  Such seem to have been the limits of his Europe, unless, perhaps, he had some vague idea of the south of Sweden.