e greatest ship, _tanquam aliud
agens_, and at any appointed minute, though a week after, either of
day or night, it shall irrecoverably sink that ship.'

A bombshell filled with gunpowder, a gunlock, and a small clock, have
been suggested as forming the components of this invention. I am
satisfied however, that several very dangerous detonating powders were
well known to the alchemists; and the condensed pocket size of the
machine described, would evidently require some such preparation.

'No. X.--A way from a mile off to dive and fasten a like engine to
any ship so as it may punctually work the same effect either for
time or execution.'

Precisely the same experiment has within a week of the time at which I
am now writing, been made at Washington, as it was by Mr. Fulton half a
century ago with his Torpedo-harpoon. If the marquis contemplated simply
human agency as the aid to apply his portable powder-machine, it must be
admitted that he had at least contemplated a more effective diving bell
than any known to modern times. Submarine transit was indeed a subject
to which he had devoted special study.

'No. XI.--How to prevent and safeguard any ship from such an
attempt by day or night.

'No. XII.--A way to make a ship not possible to be sunk, though
shot at an hundred times between wood and water by cannon, and
should she lose a whole plank, yet, in half an hour's time, should
be made to sail as fit as before.'

It is thought that a great number of airtight compartments was the
secret here hinted at; but the spirit of positive confidence with which
the marquis speaks, and the great number of successful shots which he
defies, seems to hint at something like the Ericsson Monitor of these
days. Not without interest is the following:

'No. XIII--How to make such false decks as in a moment should kill
and take prisoners as many as should board the ship, without
blowing the real decks up, or destroying them from being reducible;
and in a quarter of an hour's time should recover their former
shape, and to be made fit for any employment, _without discovering
the secret_.'

The words italicized set forth the startling marvel of the whole. It is
said that a false deck of thick plank may be easily blown into the air,
when a number of small iron boxes, open at the top, and filled with
gunpowder, are placed beneath. How this could be done