cabins, that do not
weigh anything. Allowing for everything, the weight of a ship, cargo
and all, is much lighter than its bulk of water, and consequently it
cannot sink."

"But how is it, then, that the immense bulk of a seventy-four moves so
easily in the water? One would think that its prodigious weight would
make it stick fast, and continue immoveable."

"When the seventy-four in question has displaced its weight of water,
its own weight is substituted for the water, and is in consequence
virtually annihilated; it does not, in point of fact, weigh anything
at all, and therefore is easily impelled by the wind."

"When there is any, understood," added Jack.

"And a yard or so of canvas," suggested Willis.

"True," continued Fritz, "a sail or two would be very desirable; these
instruments of propulsion do not appear, however, to have been used by
the ancients. We first hear of a sail being employed at the time when
Isis went in search of her husband Osiris, who was killed by his
brother Typhon, and whose quarters were scattered in the Nile. This
lady, it seems, took off the veil that covered her head, and fastened
it to an upright shaft stuck in the middle of the boat, and, much to
her astonishment, it impelled her onwards at a marvellous speed."

"A clever young woman that," said Willis; "but I doubt whether veils
would answer the purpose on board a seventy-four, particularly as
regards the mainsail and mizentops."

"The Phoenicians were the most enterprising of the early navigators.
They appeared to have sailed round Africa without a compass, for they
embarked on the Red Sea and reappeared at the mouth of the Nile, and
the compass was not invented till the fourteenth century."

"And who was the inventor of the compass?" inquired Willis.

"According to some authorities, it was invented by a Neapolitan named
Jean Goya; according to others, the inventor was a certain Hugues de
Bercy."

"Then," said Jack, "you do not admit the claims of the Chinese and
Hindoos, who assert priority in the discovery?"

"I neither deny nor admit their claims, because I do not know the
grounds upon which they are founded; like the invention of gunpowder
and printing, the discovery of the compass has many rival claimants."

"I am of opinion," said Jack, "that Guttenberg is entitled to the
honor of discovering printing, and that Berthold Schwartz invented
gunpowder."

"Perhaps you are right; but there is scarcely any invention