neither do the nature and objects of the present Collection of Voyages
and Travels call for any such deduction, of which an excellent epitome
will be found in the History of Geography, prefixed to Playfair's System
of Geography.

The ancients laboured under almost absolute incapacities for making
extensive voyages or discoveries by sea, proceeding from ignorance of
the form and dimensions of the earth, and other causes. They were but
indifferently versed in the practical part of astronomy, without which,
and those instruments which have been invented almost exclusively by the
moderns, for measuring the paths, distances, and relative positions of
the heavenly bodies, it is impossible to launch out with any tolerable
success or safety on the trackless ocean. They were ignorant also of
that wonderful property of the magnet or loadstone, which, pointing
invariably towards the north, enables the modern mariner to know his
precise course, at all times of the day of night, though clouds and
thick mists may hide the luminaries of heaven from his observation,
which were the only means of direction known to the ancients.

Various systems and theories appear to have prevailed among the ancients
respecting the figure and motion of the earth; some justly enough
supposing it to be a ball or sphere, suspended in infinite space, while
others conceived it to be a flat surface, floating upon and surrounded
by an interminable ocean. The just conceptions of some ancient
philosophers, respecting the spherical figure of the earth, and its
diurnal motion around its own axis, were superseded by others of a more
popular nature, and forgotten for many ages. Lactantius and Augustine,
two fathers of the catholic church, unfortunately adopted the idea of
the earth being a flat surface, infinitely extending downwards;
grounding this false notion upon a mistaken interpretation of the holy