i 
Resistance of Liquids to Solid Bodies moving in oo 235 
It may be said that such a vessel would steer bad" but we hear no 
complaint of the difficulty of steering vessels or boats with pink, or . 
sharp sterns. All the water lines should be convex in every part of 
them. As itis generally admitted that the resistance is in some pro- 
portion to the magnitude of the angle of inclination, it is evident that 
a vessel having a sharp bow, will sail faster with a given motive 
force, than another vessel of the same displacement, with a blunt or 
obtuse bow. We may obtain a very sharp bow without sacrificing 
any other good property, by projecting the lower part of the stern 
and bow in the form of a semicircle, beyond a perpendicular let fall 
from the fore part of the deck. 
About ten years ago, the writer made a model of a pleasure boat 
upon these principles, but not then residing near any navigable wa- 
ter, the boat was not built. 
The breadth was about two sevenths of the length, with a very full 
midship section and floor of the usual length, and the depth from a 
deep load water line to the upper side of the keel, was about half 
the breadth. This depth was divided into four equal parts by hori- 
zontal planes, as usual, the edges of which are called water lines, 
and were all convex in relation to the axis, in every part. ‘The an- 
gle of the bow at the first water line was 28°; at the 2d 38°; at the 
3d 40°; and at the 4th, or deep load water line, 100°. But by | 
the common method of construction, with the same length and 
breadth of deck, and a less displacement, the angles would not have 
been less than 74°, 100°, 140°, and 156°, respectively. Accord- 
ing to the results of experiments on the resistance of liquids, a boat 
or vessel built after this model, would not have more than two thirds 
of the resistance of one built after the models in common use. The 
bow of this model was formed by extending the keel to a perpendic- 
ular line from the fore part of the deck; and from a center in this 
line, a little above the 2d water line, and with a radius equal to the 
distance from the center to the keel, a semicircle was described, but 
not quite completed—being met by another curve from the top of 
the stern of much shorter radius, and in a contrary direction. The 
profile will be singular but not disagreeable when we are accustomed 
to it. 
The water lines consist of different portions of parabolic curves. 
The curves of the water lines in the direction from the stem to the 
stern, were taken from the parabola in a direction from the greatest 
ordinate towards the vertex. If we draw a rectangle, whose length 
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