"With this machine a skilful operator could swim so low on the surface
of the water, as to approach at night very near to a ship without being
discovered. After sinking quickly, he could keep at any necessary depth,
and row to a great distance in any direction, without coming to the
surface. Bushnell found, however, that much trial and instruction were
required for a man of common ingenuity to become a skilful manager. It
was first tried by his brother, who, unfortunately, was taken ill at the
time when he had become an able operator. Another person was procured,
and the first experiment tried upon the Eagle, a sixty-four, which Lord
Howe commanded in person. He went under the ship, and attempted to fix
the wooden screw into her bottom, but struck, as was supposed, a bar
of iron running from the rudder-hinge. Not being well skilled in the
management of the machine, he lost the ship in attempting to move to
another place; and, after seeking her in vain for some time, rowed a
little distance and rose to the surface. Daylight had now advanced so
that the attempt could not be renewed, and, fearing he was discovered,
he detached the magazine from his vessel and escaped. In an hour the
powder exploded, throwing a vast column of water to an amazing height,
and leaving the enemy to conjecture whether it was caused by a bomb, a
water-spout, or an earthquake. Want of resources obliged Mr. Bushnell to
abandon his schemes for that time; but, in 1777, he made an attempt from
a whale-boat against the Cerberus frigate, by drawing a machine against
her side with a line. It accidentally became attached to a schooner and
exploded, tearing the vessel in pieces. Three men were killed, and one
dangerously wounded.

"In December, 1777, Mr. Bushnell contrived another ingenious expedient
for accomplishing his favorite object. He charged a number of kegs
with powder, arranging them so as to explode on coming in contact with
anything while floating along the tide. This squadron was launched