ying Dragon_, in spots so shallow that they could be easily seen at
low water, but others sunk at least twenty fathoms deep, like that of
the _Caroline_, which had gone down in 1851, not far from Blossom Rock,
with a treasure on board of 20,000 ounces of gold. The attempt to clear
away these wrecks had also turned out very well; even sufficient
treasure had been recovered to repay all the expense, though the
preparations for the purpose by the contractors, M'Gowan and Co. had
been made on the most extensive scale, and in accordance with the latest
improvements in the apparatus for submarine operations.

Buoys, made of huge canvas sacks, coated with India rubber, and guarded
by a net work of strong cordage, had been manufactured and provided by
the _New York Submarine Company_. These buoys, when inflated and working
in pairs, had a lifting capacity of 30 tons a pair. Reservoirs of air,
provided with powerful compression pumps, always accompanied the buoys.
To attach the latter, in a collapsed condition, with strong chains to
the sides of the vessels which were to be lifted, a diving apparatus was
necessary. This also the _New York Company_ had provided, and it was so
perfect in its way that, by means of peculiar appliances of easy
management, the diver could walk about on the bottom, take his own
bearings, ascend to the surface at pleasure, and open his helmet without
assistance. A few sets likewise of Rouquayrol and Denayrouze's famous
submarine armor had been provided. These would prove of invaluable
advantage in all operations performed at great sea depths, as its
distinctive feature, "the regulator," could maintain, what is not done
by any other diving armor, a constant equality of pressure on the lungs
between the external and the internal air.

But perhaps the most useful article of all was a new form of diving bell
called the _Nautilus_, a kind of submarine boat, capable of lateral as
well as vertical movement at the will of its occupants. Constructed with
double sides, the intervening chambers could be filled either with water
or air according as descent or ascent was required. A proper supply of
water enabled the machine to descend to depths impossible to be reached
otherwise; this water could then be expelled by an ingenious
contrivance, which, replacing it with air, enabled the diver to rise
towards the surface as fast as he pleased.

All these and many other portions of the submarine apparatus which had
bee