a head sea; that in rolling their action assisted in righting the vessel; and that the wear and strain, as well on the vessel as on the engines, were materially reduced. With respect to the durability of these wheels, the commander of the FLAMER reported in January, 1834, that in six weeks of the most tempestuous weather they found them to act remarkably well, without even a single float being shifted.[40] [Footnote 38: This splendid ship is 860 tons burden, with engines of 220 horse power.] [Footnote 39: See Report quoted in Mechanic's Magazine, vol. xxii. p. 275. This saving cannot amount to less than 40 per cent. upon the whole consumption of fuel; it certainly is considerably beyond what I should have conceived to be possible; but I have no reason to doubt the accuracy of the Report. I estimate the former consumption at 10 pounds per horse power per hour, which on 220 horse-power would be 2200 pounds, of which 840 pounds = 10 bushels, would be about 4-10ths.] [Footnote 40: See a more detailed account of these reports in the Mechanic's Magazine, vol. xxii. p. 274., from which I have taken the drawing of this paddle-wheel; and also see Report of the Committee of the House of Commons on Steam Navigation to India, Evidence of William Morgan, p. 95.] This paddle-wheel is represented in figure 68. The contrivance may be shortly stated to consist in causing the wheel which bears the paddles to revolve on one centre, and the radial arms which move the paddles to revolve on another centre. Let A B C D E F G H I be the polygonal circumference of the paddle-wheel, formed of straight bars, securely connected together at the extremities of the spokes or radii of the wheel which turns on the shaft which is worked by the engine; the centre of this wheel being at O. So far this wheel is similar to the common paddle-wheel; but the paddle boards are not, as in the common wheel, fixed at A B C, &c., so as to be always directed to the centre O, but are so placed that they are capable of turning on axles which are always horizontal, so that they can take any angle with respect to the water which may be given to them. From the centres, or the line joining the pivots on which these paddle boards turn, there proceed short arms K, firmly fixed to the paddle boards at an angle of about 120°. On a motion given to this arm K, it will therefore give a corresponding angular motion to the paddle board, so as to make it turn on its pivots. At the extremities of the several arms marked K is a pin or pivot, to which the extremities of the radial arms L are severally attached, so that the angle between each radial arm L and the short paddle arm K is capable of being changed by any motion imparted to L; the radial arms L are connected at the other end with a centre P, round which they are capable of revolving. Now since the points A B C, &c., which are the pivots on which the paddle boards turn, are moved in the circumference of a circle, of which the centre