of an
undersea fighter. His book, "Inventions or Devices," published in 1578,
contains a comprehensive description of the essential characteristics of
the undersea boat as they are applied to-day. From the days of the
sixteenth century on down through the years to the present time,
submarine construction and navigation have passed through various stages
of development. Captain Thomas A. Kearney, U.S.N., in an interesting
monograph published through the United States Naval Institute at
Annapolis, says that of the early American inventors, particular mention
should be made of the work of David Bushnell and Robert Fulton, both of
whom have been termed the "father of the submarine." Bushnell's boat,
completed in 1775-6, was much in advance of anything in its class at the
time. The boat, which was, of course, water-tight, was sufficiently
commodious to contain the operator and a sufficient amount of air to
support him for thirty minutes. Water was admitted into a tank for the
purpose of descending and two brass force-pumps ejected the water when
the operator wished to rise. Propulsion was by an oar astern, working as
the propeller of a vessel works to-day. Practically Bushnell in one
attempt to destroy a British war-ship in the Hudson River was able to
get under the British frigate _Eagle_ without detection, but was unable
to attach the mine which the boat carried.

Fulton's inventive genius directed toward a submarine took tangible
shape in 1800 when the French Government built the _Nautilus_ in
accordance with his plans. Both France and the United States carried on
experimental work with Fulton's designs, under his personal supervision,
but there is no record of any marked achievement.

The first submarine within the memory of men living to-day, the first
practical, albeit crude, undersea boat, was the _H. L. Hunley_, built at
Mobile, Ala., under the auspices of the Confederate Navy and brought
from that port to Charleston on flat cars for the purpose of trying to
break the blockade of that port by Federal war-ships. The _Hunley_ was
about forty feet long, six in diameter, and shaped like a cigar. Its
motive power came from seven men turning cranks attached to the
propeller-shaft. When working their hardest these men could drive the
boat at a speed of about four miles an hour.

Several attempts to use the _Hunley_ were unsuccessful, each time it
sank, drowning its crew of from eight to ten men. These experiments,
which