"A necessity occurs in war, on many occasions, which leaves no option of
choice in occupying posts of an unhealthy character: but there is,
unfortunately, an authority, derived from example and the sanction of
great names, which directs the military officer, when under no military
necessity, to fix his encampment on grounds which are unhealthy in
themselves, or which are exposed by position to the influence of noxious
causes, which are carried from a distance.
"Such advice proceeds from the desire to act on a presumption of
knowledge, which cannot be ascertained, rather than to act by the
experience of facts, which man is qualified to observe and verify.
"It is consonant with the experience of military people, in all ages and
in all countries, that camp diseases most abound near the muddy banks of
large rivers, near swamps, and ponds, and on grounds which have been
recently stripped of their woods. The fact is precise: but it has been set
aside to make way for an opinion.
"It was assumed, about half a century since, by a celebrated army
physician, that camp diseases originate from causes of putrefaction, and
that putrefaction is connected radically with a stagnant condition of the
air. As streams of air usually proceed along rivers, with more certainty
and force than in other places, and as there is evidently a more certain
movement of air, that is, more winds, on open grounds than among woods and
thickets, this sole consideration, without any regard to experience,
influenced opinion, and gave currency to the destructive maxim, that the
banks of rivers, open grounds, and exposed heights, are the most eligible
situations for the encampment of troops. They are the best ventilated:
they must, if the theory be true, be the most healthy. The fact is the
reverse. But demonstrative as the fact may be, fashion has more influence
than multiplied examples of fact, experimentally proved.
"Encampments are still formed in the vicinity of swamps, or on grounds
which are newly cleared of their woods, in obedience to theory, and
contrary to fact. The savage, who acts by instinct, or who acts directly
from the impressions of experience, has in this instance the advantage
over the philosopher, who, reasoning concerning causes he cannot know, and
acting according to the result of his reasonings, errs and leads others
astray by the authority of his name.
"The savage feels, and acting by the impression of what he feels, instead
of fixing his habitation on the exposed bank of large rivers, unsheltered
heights, or grounds newly cleared of their woods, seeks the cover of the
forests, even avoids the streams of air which proceed from rivers, from
the surface of ponds, or from lands newly opened to the sun. The rule of
the savage is a rule of experience, founded in truth, and applicable to
the encampment of troops, even of civilized Europeans.
"In accordance with this principle, it is almost uniformly true, _caeteris
paribus_, that diseases are more common, at least more violent, in broken,
irregular, and hilly countries, where the temperature is liable to sudden
changes, and where blasts descend with fury from the mountains, than in
large and extensive inclined plains, under the action of equal and gentle
breezes only. From this fact, it becomes an object of the first
consideration, in choosing ground for encampments, to guard against the
impression of strong winds, on their own account, independently of their
proceeding from swamps, rivers, and noxious soils.
"In countries covered with woods, abundantly supplied with straw, and
other materials applicable to the purpose of forming shelter, it is, upon
the whole, better to raise huts and construct bowers than to carry canvas.
The individual is exercised by labor, and as his mind is employed in
contriving and executing something for self-accommodation, he is furnished
with a daily opportunity of renewing the pleasure. The mode of hutting,
here recommended, effectually precludes the evils arising from those
contaminations of air in which contagion is generated--an evil which often
arises in tents, and is carried about with an army in all its movements in
the field."
* * * * *
The view of the ancients in regard to the encampment of troops may be
understood from the counsel of Vegetius: "Ne aridis et sine opacitate
arborum campis, aut collibus ne sine tentoriis aestate milites
commorentur."