In 1835, Mr. Elijah Galloway obtained a patent for a paddle-wheel, which is free from many of the objections to which other inventions forthe same objectare liable. It is equally simple as the common wheel (of which it is in fact a modification), and is as little liable to derangement, and from the extensive adoption of it in steam vessels of all descriptions, we may infer that it possesses considerable advantages, having the whole depth of the float of one unbroken area; the floats are in divided portions, whereby the concussion on entering the water, and the amount of the back water, are greatly reduced.
a a in the figure, which is a side elevation of the wheel, represents the circle, or course of the outer edges of the floats; and b b the circle bounding the inner edges of the floats; g g g g are a series of portions of floats, which are set on curved lines, approximating to the cycloidal line d f at their outer edges, and are securely affixed to the paddle-wheel by screw-bolts and nuts or other means. Now it will be obvious, if the paddle-wheel be supposed to be revolving in the direction of the arrow, and the vessel going at such speed as that her velocity is equal to that of the inner circle b b, then the bars constituting one paddle would enter the water at the point f or nearly so, and displace very little more water than that disturbed by the lowest bar. Thus the waste of power attendant on the common radial float board is obviated, and the concussion produced thereby almost entirely avoided.