SUBMARINE NAVIGATION. 



159 



In the latter half of the eighteenth century, an engineer named Day 

 made one successful dive in the harbor of Plymouth, England, in a 

 boat of his own designing. He went down a second time and did not 

 return. 



It may be said in general that the necessities and opportunities of 

 war have always been the greatest, indeed, almost the only incentive to 

 experiments under water. The War of Independence proved remark- 

 ably stimulating to submarine invention. In 1775 David Bushnell, of 

 Connecticut, constructed a diving boat for use against English men-of- 

 war. A minute description of this boat is contained in a letter written 

 by him to Thomas Jefferson in 1787. It resembled externally two 

 upper turtle shells joined together by their edges, whence its name 

 'Tortoise.' It carried a crew of one man, but this man was not David 



Fig. 1. The Confederate Submarine Boat which Sank the U. S. Steamship ' Housatonic 

 in Charleston Harbor During the Civil War. 



Bushnell, as it appears! During the harbor trials the boat was con- 

 nected with the dock by means of a rope so that it might be recovered 

 in case of accident. David Bushnell manipulated the safer end of 

 this rope on the dock, while his brother, Ezra, and afterwards Sergeant 

 Lee, did their best to learn the proper use of the mechanism within. 



The following year, the first of the war, Sergeant Lee steered the 

 'Tortoise' beneath the hull of the British ship 'Eagle,' of 64 guns, 

 lying off Governor's Island in New York harbor. He attempted to 

 fix to her bottom a torpedo by means of a wood screw, but being 

 rather unskillful still in maneuvering the 'Tortoise,' he lost the 'Eagle' 

 altogether and was finally forced to the surface for air. Daybreak 

 prevented further operations at that time. Two similar attempts were 

 afterwards made on the Hudson, but they also failed and the 'Tortoise' 

 was finally sunk by a shot. 



