By their observations we have acquired a great knowledge as to the nature and variation of winds, particularly the monsoons, or trade winds, and other periodical winds, of which the ancients had not the least conception; and by these helps we not only have it in our power to proceed much farther in our discoveries, but we are likewise delivered from a multitude of groundless apprehensions, that frightened them from prosecuting discoveries.  We give no credit now to the fables that not only amused antiquity, but even obtained credit within a few generations.  The authority of Pliny will not persuade us that there are any nations without heads, whose eyes and mouths are in their breasts, or that the Arimaspi have only one eye, fixed in their forehead, and that they are perpetually at war with the Griffins, who guard hidden treasures; or that there are nations that have long hairy tales, and grin like monkeys.  No traveller can make us believe that, under the torrid zone, there are a nation every man of which has one large flat foot, with which, lying upon his back, he covers himself from the sun.  In this respect we have the same advantage over the ancients that men have over children; and we cannot reflect without amazement on men’s having so much knowledge and learning in other respects, with such childish understandings in these.

By the labours of these great men in the two last centuries we are taught to know what we seek, and how it is to be sought.  We know, for example, what parts of the north are yet undiscovered, and also what parts of the south.  We can form a very certain judgment of the climate of countries undiscovered, and can foresee the advantages that will result from discoveries before they are made; all which are prodigious advantages, and ought certainly to animate us in our searches.  I might add to this the great benefits we receive from our more perfect acquaintance with the properties of the loadstone, and from the surprising accuracy of astronomical observations, to which I may add the physical discoveries made of late years in relation to the figure of the earth, all of which are the result of the lights which these great men have given us.

It is true that some of the zealous defenders of the ancients, and some of the great admirers of the Eastern nations, dispute these facts, and would have us believe that almost everything was known to the old philosophers, and not only known but practised by the Chinese long before the time of the great men to whom we ascribe them.  But the difference between their assertions and ours is, that we fully prove the facts we allege, whereas they produce no evidence at all; for instance, Albertus Magnus says that Aristotle wrote an express treatise on the direction of the loadstone; but nobody ever saw that treatise, nor was it ever heard of by any of the rest of his commentators.  We have in our hands some of the best performances of antiquity in regard to geography, and any man who has eyes,