visited
in the voyage, and gives little or no information respecting these
particulars.

The _rutter_ or journal must be allowed to be very curious.--The author,
like an exact and diligent navigator, has not only given the course and
distance from one place to another, with the latitudes of the principal
ports and head-lands; but has noticed the minute windings of the coast,
and the situations of islands, with observations on the tides, currents,
shoals, sand-banks, and other particulars respecting the Red Sea. Yet,
far from confining himself to mere nautical remarks, he has given an
account of all the places at which he touched, together with accounts of
the countries and the inhabitants, so far as he was able to collect from
his own observations, or the accounts of such as he was able to converse
with, particularly the natives. Don John hath gone farther yet, and has
even attempted to draw a parallel between the ancient and modern
geography of this sea. If in all points of this last he may not have
succeeded, the great difficulty of the task, owing to the obscurity of
the subject, is to be considered: most of the ancient places having been
destroyed; the ancient names of others long since out of use and
forgotten; and that very little is known of these coasts by Europeans,
even at this day. For these reasons, as the conjectures of the author
are often erroneous respecting the ancient geography, and as at best
they are very uncertain, we shall for the most part _insert them by way
of notes_, with our own remarks respecting them[256]. Whether the
_altitudes_ have been taken by Don Juan with that precision which
geography requires, may also be in some measure questioned; since we
find there was a _crack in the instrument employed_, the size of which
is not mentioned; neither were all the observations repeated. Even if
they had been, it is well known that the observations of those times
were by no means so accurate as those made of late years. After all,
however, the observations in this journal appear to have been made with
a good deal of care, and they cannot fail to be of great service to
geography.

[Footnote 256: In this edition, which has been taken from that by
Purchas, these conjectures of Don Juan de Castro are restored to the
text: but the remarks by the Editor of Astleys Collection are all
retained in notes.--E.]

It is alone by the observations contained in this journal that
geographers are able to determi