[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 determine the extent of the Arabian Gulf or Red
Sea from north to south[257], as well as the situation of its principal
ports on the west side. The latitude of the straits was verified by the
observations of Don Juans pilot. But as most maps and charts give the
situation of Suez, at the northern end of the Red Sea, very different
from that marked in this journal, which is 29 deg. 45' N. it may not be
amiss to examine this point.
[Footnote 257: The modern knowledge of the Red Sea has been much
augmented by the labours of Bruce, Nieubur, Lord Valentia, and others,
which will be given in a future division of our work. - E.]
By several very accurate observations made in 1694, M. Chazelles of the
Royal Academy of Paris found the latitude of Cairo to be 80 deg. 2' 20". The
difference of latitude therefore between Cairo and Suez, will be 17
minutes; which we conceive cannot be very far from the truth, if not
quite exact, since the map published by Dr Pocock makes the difference
about 20 minutes. It is true that in Sicards map of Egypt, and in a
late[258] French chart of the eastern ocean, Suez is placed only two
or three minutes to the southward of Cairo. But as these authors had no
new observations made at Suez to go by, and seem to have been
unacquainted with those of Don Juan de Castro, their authority can weigh
very little against an express observation, and against Dr Pococks map,
which, among other helps, was constructed upon one made by the natives.
Besides this, in his later maps De L'isle regulates the situation of
Suez according to the latitude found by Don Juan. Indeed Sicard places
Suez nearly in that parallel, but egregiously mistakes the latitude of
Cairo, so that he seems to have given it that position more by chance
than design.
[Footnote 258: It is proper to remark here that the collection of Astley
was published in 1745, sixty-seven years ago. - E.]
This may suffice to support the credit of the observations of latitude
as made by Don Juan, till new and better ones can be made, which we are
not to expect in haste, as European ships now seldom sail any farther
into the Red Sea than Mokha or Zabid, for which reason this journal
is the more to be prized.
