"If such an animal is in existence, if it inhabits the depths
of the ocean, if it frequents the strata lying miles below
the surface of the water, it must necessarily possess an
organisation the strength of which would defy all comparison."

"And why this powerful organisation?" demanded Ned.

"Because it requires incalculable strength to keep one's self
in these strata and resist their pressure. Listen to me.
Let us admit that the pressure of the atmosphere is represented
by the weight of a column of water thirty-two feet high.
In reality the column of water would be shorter, as we are
speaking of sea water, the density of which is greater than
that of fresh water. Very well, when you dive, Ned, as many
times 32 feet of water as there are above you, so many times
does your body bear a pressure equal to that of the atmosphere,
that is to say, 15 lb. for each square inch of its surface.
It follows, then, that at 320 feet this pressure equals
that of 10 atmospheres, of 100 atmospheres at 3,200 feet,
and of 1,000 atmospheres at 32,000 feet, that is, about 6 miles;
which is equivalent to saying that if you could attain this
depth in the ocean, each square three-eighths of an inch
of the surface of your body would bear a pressure of 5,600 lb.
Ah! my brave Ned, do you know how many square inches you carry on
the surface of your body?"

"I have no idea, Mr. Aronnax."

"About 6,500; and as in reality the atmospheric pressure is about 15 lb.
to the square inch, your 6,500 square inches bear at this moment a pressure