89 
Resistance of plain conical-bow 100+10 for resistance of 
flanges + 5 for friction =115. Available power, one-half 
of 100 = 50 — 15 = 35 clear gain. This is upon the suppo- 
sition that the revolving-cone is only checked to the extent 
of half the speed due to the resisting water.” 
Several experiments were then tried. 
A laden model was balanced in the stream by a weight, 
and then a string attached to the shaft of the propeller, which 
revolved six times the speed of the bow. The string was 
fastened ahead, and the model wound itself forward. A 
second model was placed in the stream without a balance- 
weight, and it pulled itself ahead by a string fastened to the 
cone-shaft. A craft was then produced (merely as an illus- 
tration) with a paddle both at the head and stern, with gear- 
ing to increase the speed of the hind-paddle. When this is 
balanced in the stream, the fore-paddle causes the hind-paddle 
to revolve, and in doing so it pushes the boat forward by its 
action against the water at the stern. 
In the discussion which followed the reading of the Paper, 
the President said it was impossible to take power from the 
water without decreasing the speed of the ship to the extent 
of the power gained. Mr. Morris replied that no doubt 
that was so ; but in this instance the water treated was not 
that which passed the sides of the vessel, but the very water 
which she would have to displace by her motive power before 
she could pass through it. Dr. Joule thought that the effect of 
the revolving-bow might in some cases be to make a bad bow 
better ; but denied the possibility of its producing any but a 
retarding effect if applied to a ship possessing good lines. 
