ssity requires Parties to be landed for Wood or Water, or on
other Duties, they should always be obliged to return and lie aboard
at Night; and if that cannot be done, they should be cautioned to
avoid lying down to sleep on the Grass, where the Air is fresh, or
they are exposed to the Dews; and to pitch their Tents on a rising
Ground, covered with Straw or dried Reeds, and a Blanket; and to use
the other Precautions necessary for encamping in these warm Climates;
for where this Care has been neglected, the Consequences have
frequently proved fatal[140].

[140] A very remarkable Instance of this we have related by
Dr. _Lind_. In the Year 1739, in _Mahon_ Harbour, a Party of
Men were sent with the Coopers from Admiral _Haddock_'s Fleet
to refit and fill the Water Casks, who, finding an artificial
Cave dug out of a soft sandy Stone, put their bedding into
it; every one who slept in this damp Place was infected with
the Tertian Fever, then epidemic in _Minorca_, and not one in
eight recovered. At the same Time the Men aboard the Ships
continued healthy; and others, who were afterwards sent on
the same Duty, enjoyed perfect Health by being obliged to
sleep in their respective Ships. He says, he has known a
whole Boat's Crew seized next Morning with bad Fevers by
sleeping near the Mangroves, with which the Sides of the
Rivers are frequently planted in the Torrid Zone. _Ibid._ p.
74, 75.

On unhealthful Coasts, the noxious Land Vapours often affect the Crews
of Ships that run up into Rivers or Harbours, and cause great
Sickness; and therefore in such Places Ships should anchor at as great
a Distance from the Shore as can well be done, that they may be
exposed to the Sea Breezes, and as much to the Windward of the Woods
and Marshes as possible; and if the Anchorage is safe, one should
prefer the open Sea to running up into Rivers or Creeks[141].

[141] The higher that Ships sail up the Rivers upon the Coast
of _Guinea_, the more sickly they become: Such, however, as
keep at Sea beyond the Reach of the Land Breezes (that is,
two or three Leagues at Sea), are for the most part healthy.
_Lind_, _ibid._ p. 65. The Malignity of these Land Vapours
often does not extend itself to any considerable Distance, as
we know by manifold Experience. The Troops in _Zealand_ were
very unhealthy when Admiral _Mitchel_'s Squadron, which lay
but a