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 reward of the wolf for using his long neck and bill as a forceps in extracting a bone from the latter’s oesophagus, Lupus suggests that for the crane to have had his head down in the lupine throat and not get it snapped off was reward enough for any reasonable fowl.  The petty officer was sufficiently learned in the Lyceum to administer a like return.  The stipulated salvage was never paid or offered.[A]

[Footnote A:  It was a warrant-officer of the Milwaukee:  I do not wish to be more definite; but the money (fifty dollars) may be sent to the editor of this Magazine, who will forward it to the diver.]

The monitors had small square hatches or man-ports let into the deck, admitting one person conveniently.

  Hinc via, Tartanii quae fert Acherontis ad undas.

A swinging ladder, whose foot was clear of the floor, led down into the recesses.  A diver, having completed his task, ascended the treacherous staircase to escape, and found the hatch blocked up.  A floating chest or box had drifted into the opening, and, fitting closely, had firmly corked the man up in that dungeon, tight as a fly in a bottle.  From his doubtful perch on the ladder he endeavored to push the obstacle from its insertion.  Two or more equal difficulties made this impossible.  The box had no handle, and it was slippery with the ooze and mucus of the sea.  The leverage of pushing only wedged it faster in the orifice.  The inconstant ladder swayed from it as a fulcrum.  Again and again by art and endeavor and angle of push he essayed, and the ladder made sport of it.  It was deadly sport, that swing and seesaw on the slippery rungs in the immeasurable loneliness of the silent, shrouded cabin.  It was no rush of air, sending life tingling in the blood made brilliant with carmine of oxidation, but the dense, mephitic sough of the thick wool of water.  He descended and sat upon the floor to think.  Feasible methods had failed, and the sands of his life were running out like the old physician’s.  Now to try the impracticable.  There are heaps of wisdom in the wrong way sometimes, which, I suppose, is the reason some of us like it.  The box was