Griswold on Submarine Explosion. 97 
the observation of Mr. Lee, amidst the hurry and constant 
anxiety attendant upon such a perilous navigation. 
But not the least ingenious part of this curious machine, 
was that by which the horizontal motion was communicated 
to it. ‘This object was effected by means of two oars or 
paddles, formed precisely like the arms of a wind-mill, 
which revolved perpendicularly upon an axletree that pro- 
jected in front ; this axletree passed into the machine at a. 
water joint, and was furnished with a crank, by which it | 
was turned: the navigator being seated ede. with one. 
hand laboured at the crank, ane with the other steered by 
the tiller. 
The effect of. paddles so constructed, and turned in the 
manner stated, by propelling or rather drawing a body after 
_them under water, will readily occur to any one without 
explanation. 
These paddles were but twelve inches long, and about 
four wide. Two smaller paddles of the same description, 
also projected near the head, provided with a crank instde,_ 
by which the ascent of the machine could be assisted. 
By vigorous turning of the crank, says my informer, the 
machine could be propelled at the rate of about three miles 
an hour in still water. When beyond the reach of danger, 
or observation of an enemy, the machine was suffered to 
float with its head just rising from the water’s surface, and 
while in this situation, air was constantly admitted through 
three small orifices in the head, which were closed when a 
descent was commenced. 
The efficient part of this engine of devastation, its maga- 
zine, remains to be spoken of. ‘This was separate and dis- 
tinct from the machine. It was shaped like an egg, and 
like the machine itself, was composed of solid pieces of oak 
scooped out, and in the same manner fitted together, and 
secured by iron bands, &c. One hundred and _ thirty 
pounds of gun powder, a clock, and a gun lock, provided 
with a good flint that would not miss fire, were the apparatus 
which it enclosed. This magazine was attached to the 
back of the machine, a little above the rudder, by means of | 
a screw, one end of which passed quite into the magazine, 
and there operated as a stop upon the movements of the 
clock, whilst its other end entered the machine. This 
screw could be withdrawn from the magazine, by which 
Vou. Il.....No. 1. 13 
