detected; and therefore, when they intrude their supposititious productions on the public, they make no conscience of boasting, at the same time, with how much skill and care they have been executed.  But let not those who are unacquainted with naval affairs imagine, that the impositions of this kind are of an innocent nature; for, as exact views of land are the surest guides to a seaman, on a coast where he has never been before, all fictions, in so interesting a matter, must be attended with numerous dangers, and sometimes with the destruction of those who are thus unhappily deceived.[7]

[Footnote 7:  It must be quite obvious to all who are in the least degree acquainted with the nature of these draughts and views of land, in the nature of a coasting pilot, that it is utterly impossible to reduce them within the compass of an octavo size, and at the same time to render them of the smallest degree of usefulness; while large plates must have been necessary, and speedily destroyed by opening and refolding.—­E.]

Besides these draughts of such places as Mr Anson, or the ships which he commanded, have touched at in the course of this expedition, and the descriptions and directions relating thereto, there is inserted, in the ensuing work, an ample account, with a chart annexed to it, of a particular navigation, of which hitherto little more than the name has been known, except to those immediately employed in it:  I mean the tract described by the Manilla ship, in her passage to Acapulco, through the northern part of the Pacific-ocean.  This material article is collected from the draughts and journals met with on board the Manilla galleon, founded on the experience of more than an hundred and fifty years practice, and corroborated in its principal circumstances by the concurrent evidence of all the Spanish prisoners taken in that vessel.  And as many of their journals; which I have examined, appear to have been not ill kept, I presume the chart of that northern ocean, and the particulars of their routes through it, may be very safely relied on by future navigators.  The advantages which may be drawn from an exact knowledge of this navigation, and the beneficial projects which may be formed thereon, both in war and peace, are by no means proper to be discussed in this place; but they will easily offer themselves to the skilful in maritime affairs.  However, as the Manilla ships are the only ones which have ever traversed this vast ocean, except a French straggler or two, which have been afterwards seized on the coast of Mexico; and as, during near two ages, in which this trade has been carried on, the Spaniards have secreted with the utmost care all accounts of their voyages from the rest of the world; these reasons would alone authorize the insertion of those papers, and would recommend them to the inquisitive, as a very great improvement in geography, and worthy of attention, from the singularity of many circumstances therein recited.