sense of touch the only reliance, and the life-line his guide.

But the peril incurred can be better understood through an
illustrative example of a perilous adventure and a poor return.
Officers and men of the unfortunate monitor asked for the rescue of
their property, allowing a stipulated sum in lieu of salvage. Among
these was a petty officer, anxious for the recovery of his chest.
It involved peculiar hazards, since it carried the diver below
the familiar turret-chamber, through the _inextricabilis error_ of
entangling machinery in the engine-room, groping among floating and
sunken objects, into a remote state-room, the Acheron of the cavernous
hold. He was to find by touch a seaman's chest; handle it in that
thickening gloom; carry it, push it, move it through that labyrinthine
obscurity to a point from which it could be raised. To add
immeasurably to the intricacy of this undertaking, there was the need
of carrying his life-line and air-hose through all that entanglement
and obscurity. Three times in that horror of thick darkness like wool
the line tangled in the web of machinery, and three times he had, by
tedious endeavor, to follow it up, find the knot and release it. Then
the door of the little state-room, the throat of exit, was shut to,
and around and around the dense chamber he groped as if in a dream,
and could find no vent. All was alike--a smooth, slimy wall, glutinous
with that gelatinous liquid, the sea-water. The tangled line became a
blind guide and fruitful source of error; the hours were ebbing away,
drowning life and vital air in that horrible watery pit;

Aut hoc inclusi ligno occultantur Achivi,

or, a worse enemy than the subtle Greek's, death from the suspended
air-current. Speed, nimbleness, strength and activity were worthless:
with tedious fingers he must follow the life-line, find its
entanglements and slowly loosen them, carefully taking up the slack,
and so follow the straightened cord to the door. Then the chest: he
must not forget that. Slowly he heaves and pushes, now at this, now
at the life-line hitching on knob, handle, lever or projecting peg--on
anything or nothing in that maze of machinery; by involution and
evolution, like the unknown quantity in a cubic equation, through all
the twists, turns, assumptions and substitutions, and always with that
unmanageable, indivisible coefficient the box, until he reaches the
upper air.

In Aesop's fable, when the crane claimed the