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PELLING VESSELS. Mr. Henry Booth, whose name is so “facts in natural philosophy never conhonourably identified with the rise and tradict themselves.” If Mr. Booth will progress of the railway system in this read and ponder well the “Experimental country, has recently been applying his Equiry" (1794) of our first authority on active and sagacious mind to the kindred this as on other mechanical subjects, subject of steam navigation ; and the re John Smeaton, a work which we cannot sult has been the discovery of what he believe he has ever seen-we are perconsiders to be an improved method of suaded (such is our impression of his haapplying steam power to the propulsion of bitual candour) that he will himself acvessels through water, for which he has knowledge that he is altogether in the obtained letters patent, and a pamphlet wrong; and in the hope that he will do so now before us, (anticipatory of his spe soon, and that such will be the happy result cification,) in which the principles and of his self-examination, we shall refrain details of that method are very fully, and for the present from entering more parwe need hardly add, very cleverly ex ticularly into his very singular heresy. plained. *

We cannot, however, quit the subject The pamphlet opens with an investi -even for the present-without expressgation of the received doctrine that the ing by the way our extreme surprise, to mechanical power expended in giving see it asserted by so great an authority in different degrees of velocity to bodies railway matters as the treasurer of the propelled through water is as the squares Liverpool and Manchester Railway, of that velocity. Mr. Booth“ demurs that, to double any given speed on entirely” to the correctness of this doc railways, all that is wanted is double trine. He says it is not at all recognized the power. Seldom has there been on railways, where the established rule a greater mechanical mistake promulis, that “ if five horse-power will accom gated. If this is to be taken as a sample plish five miles an hour, ten horse-power

of the received doctrines on railways, will effect ten miles an hour," and so on;

no wonder the received dividends are so and he endeavours to show, both by ar unexpectedly, and hitherto so unaccountgument and by experimental evidence, ably, small. It is of the same class of that it comes all of grievous theoretical fallacies exactly, as the oft-exploded one blundering, that it has been recognised in political economy, that the product of anywhere else. With the high respect 2 x 2 is always, and of necessity, 4. which we entertain for Mr. Booth, it

What Mr. Booth’s heresy in regard to gives us great pain to be under the neces the theory of the quadruple ratio has to sity of saying at once that, so far, his do with his patented improvements in pamphlet is a most signal failure. It is ship-propelling, he does not explain ; and evident, in the first place, from his state fortunately, perhaps, for the reputation of ment of the "rationale of the quadruple the latter, it is not easy to discover. In ratio," that he does not understand what point of fact, there is no connexion between he has undertaken to refute; and, in the them. The one may be exceedingly next place, some of the comparative ex erroneous (as we take it to be), and the periments which he cites, are admitted other not in the slightest degree affected by himself to be entirely in favour of the by it. quadruple ratio, while others are as dia The patented improvements of Mr. metrically opposed to it-a circumstance Booth may be described generally as of opposition which indicates, of necessi consisting in a concentration of the mety, some great error in the conditions of chanical power employed in steam-vesthe experiments; for, as he truly observes sels; and this concentration his pamphlet

leads us to consider under two heads,• The Theory and Practice of Propelling first, a concentration of the power exerted through Water, with Observations on the Compara by the paddle-wheels; and second, a contive Resistance offered by Water to Bodies moving through it at different Velocities, comprising also a

centration of the power produced by the Description of an improved method of applying steam-engines. Mechanical Power to steam Navigation.- By Henry Booth, 46 pp. 8vo. Banes, Liverpool; Weale, Lon

First, then, as to the concentration of the power exerted by the paddle-wheels,


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Fig. 5.

the following is Mr. Booth's own explanation of the means he has contrived for this purpose :

“ The principle, I suggest, consists in a concentration of nearly the whole force of the engine or moving power, into one-tenth or other small portion of each stroke of the piston; and I make use of such concentrated force to effect a proportionably powerful stroke with the propellers ; the momentum of the vessel so gained carrying it onwards, through the water, till the next stroke. The moving levers or beams (B), through which the power is communicated, are worked by an engine or engines in the ordinary or most approved way: C No. 1 and 2, figure 1, are cam wheels, which I employ to communicate the power of the engine to an upright lever L, vibrating on its axis (A) at its foot, and connected at the top by rod and crank with the main shaft S, to which the propellers are attached. The crank or short lever, thus fixed to the main shaft inside of the vessel, corresponds in its movements with the propellers, fixed to the same shaft outside the vessel. P is the propeller-one on each side of the vessel-serving instead

of the paddle wheel ; the portion of it to which the water offers resistance, and by means of which the vessel is propelled, consisting of a valve plate (V) working on hinges like a valve or door, kept close by a moveable cross-bar, when forced in the direction required to propel the vessel ; and, on the return motion opening on its hinge or axis, and yielding to the water, so as to offer little or no resistance ; the movement of the propeller or single paddle being vibratory, backwards and forwards, instead of the rotary movement of the ordinary paddle wheel.

“ It will be perceived, that when the working beam is in motion, and the cam wheel No. 1 is made to revolve in the direction indicated by the arrow, the cam which occu. pies about one-tenth part of the wheel's circumference, and which is shaded dark in the drawing, communicates motion to the upright lever L, through the friction wheel F, which moves between and receives its motion from the two cam wheels, and thus causes motion to the crank and main shaft, and consequently to the propellers. The forward or principal motion is effected in onetenth portion of the whole revolution of the cam wheels (or double stroke of the piston),

the cam of wheel No. 1 occupying about vibrating or bell-crank motion. This crank, one-tenth of the periphery of the cam wheel, or short lever, I suppose 4 feet long, and while the return motion of the lever L, attached to the main shaft, to which the probringing back the propellers with the valves pellers also are attached (one on each side or leaves open (V figure 5), is effected slowly, the vessel), and the propellers I suppose to by means of the extended cam, on the wheel be 20 feet long from the main shaft to the No. 2, also shaded dark, which moves in the centre of the valve plates, or paddle boards, same direction, as indicated also by the or five times the length of the main crank, arrows. This cam (No. 2) comes into ope (10 feet from the shaft to the water, and 10 ration when the other cam ceases to act, and feet deep in the water); the paddles or occupies about nine-tenths of the periphery valve plates, therefore, will make a stroke of the wheel No. 2. The return motion, of 121 feet, while the crank end moves therefore, of the lever (L), and consequently 2 feet 6 inches in the same direction. Now, of the propeller, is about nine times slower this movement or stroke of 123 feet in the than the primary motion effected by the water, is effected while the cam wheel No. cam of the wheel No. 1, the engine working 1 moves one-tenth part of a revolution, equably throughout. The upper end of the or that portion of the revolution which lever L, we have stated, is connected with effects the action of the cam No. 1 against the main crank (MC) which is attached to the upright lever L, in the forward movethe main shaft (S), and moves simultaneous ment of the engine; consequently, the proly, and in the same direction as the propellers, pelling stroke of 12 feet in the water is constituting mechanically a lever of the third effected while the engine piston moves one class. But the crank being only 4 feet in foot, or one-tenth of a double stroke. If length, to a propeller of 20 or 24 feet radius, the piston, therefore, moves at the rate of the velocity of the extreme end of the pro two miles and a half an hour, the propellers peller—that is, of the closed valve plate or will move through the water at the rate of paddle-board, is proportionably more rapid, 24 by 124, or 314 miles an hour ; the in. and being also a great depth below the sur crease of speed being effected by the quiet face of the water, the effectiveness of the and smooth motion of the levers; the centre propeller is multiplied in a greatly increased or bearing point of the lever L moving only ratio.

1 foot 3 inches in each direction, with each “Now, the mode of operation is as fol. double stroke of the piston. lows in the forward or ordinary movement “The speed of the propelling valve plate of the engine :—The cam wheels, No. 1 and is here stated at thirty-one miles per hour, 2, are moved round in the same direction but it is obvious that this may be varied by by cranks and connecting rods, communi varying the size of the cam or the proporcating with the reciprocating beam in the tion of the levers or cranks; or by modifyordinary way, regulated by the slow uniform ing the sweep of the cam, the velocity of the speed of the engine piston, which I will propeller may commence at 12 or 14 miles suppose 2} miles per hour. The dimensions an hour, (a little below the supposed speed of the engine, cam wheels, levers, &c., must of the vessel, and therefore producing no obviously vary with the size of the vessel shock), and gradually increase to 30 or 35 and other circumstances. In this descrip- miles, and then diminish down to 15 or 20 tion, I suppose the engine or engines to have miles an hour before the end of the stroke. a five feet stroke-the cam wheels to be 10 “ Still further, to render smooth the mofeet diameter each, making one revolution tion of the propeller, a range of springs is with each double stroke of the engine. The placed on each side of the valve plate, to cam attached to the periphery of the wheel render the shutting action of the plate against No. 1 in the forward movement, extends the supporting cross-bar smooth and gradual, along 3 feet of the circumference (about one the springs assisting the opening movement tenth of the whole), and projects 15 inches of the valve plate on the return motion of from the circumference in its extreme action, the propeller. Thus, every thing like shock which is consequently the extent of motion or percussion in the action of the propeller communicated to that point of the lever L, is to be avoided, and a smooth and nearly which forms the centre or axis of the friction uniform motion imparted to the vessel. wheel F. This point is half way between " It is thus evident that the propelling the pivot or axis A, on which the upright movement is accomplished in about one-tenth lever rests and vibrates, and the upper end of a revolution of the cam wheel, or one-tenth E; consequently, the upper end E noves of a stroke of the engine piston. The duty of 2 feet 6 inches, while the cam communicates the engine during the remaining nine-tenths a motion of 1 foot 3 inches to the centre of of the stroke being to bring back, at a slow the vibrating lever. The upper end of the speed, the propeller with open valve, to keep lever being connected with the main crank up the momentum of the heavy cam wheels, MC, communicates to it a 2 feet 6 inch and quietly to raise the piston of the pneu

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matic cylinder, which, by its descent is to valves open, is principally employed in acassist the principal movement or rapid cumulating the reserved power, of which we stroke of the propeller."'--pp. 22–27. shall speak hereafter--keeping up the motion

“ Figs. 2, 3, 4, and 5, are separate of the heavy cam wheels, and thus preparing drawings of the propeller, shown during the for the next great stroke of the propellers." action of the valve-plate, and the mode in which it may be thrown out of gear or put into back gear, either on one side or both

Mr. Booth illustrates this view of the sides of the vessel—or it may be thrown out efficacy of his reciprocating propellers by of gear on one side, and continued in gear on the following instances the other side-or be put in back gear on one side, and forward gear on the other side, “ In thus concentrating the moving power when it is wanted to bring the vessel quickly into a short interval of time, with afterwards round; the utility of all which operations a respite during a longer interval, and so on will be obvious to nautical men.

alternately, we copy the natural movements “ Fig. 2, is a front view of the propeller of those animals whose element is the water. with the valve-plate closed, (V) the lower A fish, by the muscular exertion of the tail, edge supported by the sliding cross-bar 0. is propelled rapidly forward by one strenuThis bar has a motion up and down of about ous effort, after which the momentum gained 3 inches, effected by a lever on deck, attached is sufficient to keep up the motion till the to the bar by two connecting-rods r r. muscles have recovered their tone for another When it is lowered down, the valve-plate is stroke. The same plan of operation is purloose, and will move backwards and forwards sued in a fast-rowing boat where a rapid and on its hinge or axis A A, having no power to powerful stroke is effected with the aggrepropel the vessel either backwards or for gate power at command, after which there is wards; but when the bar is raised 3 inches, an interval occupied by the returning movethe lower edge of the valve-plate is forced ment of the oar, during which the strength by the water against the cross-bar 0, and is recruited for another effort; the momenthe propeller comes into action-and it is tum gained, carrying the boat forward in the evident that, according as this sliding-bar interval. The principle and general mode is raised at the front or back of the valve of operation which I propose appears thus plate, the propeller will become efficient to to be sanctioned by the motion of fishes in move the vessel either forwards or backwards, their own element, and by the operation of which may be done in a second of time at our swiftest boats moved by manual power, the option of the engineer, on one side of in which latter case the alternate effort and the vessel or both, and either with or with relaxation is altogether optional ; as in a our reversing the engine.

boat of six oars, instead of pulling all toge“Fig. 3 is a side view of the propeller, ther, the rowers might, if they pleased, pull showing the moveable bar and connecting -two, and two, and two, keeping up, alrod, guided in a slot behind the bottom of most without intermission, a multiplicity the valve-plate—the connecting-rod (r) ex and continuous succession of small pulls, intending up to the deck, where it is worked stead of a comparatively few vigorous strokes, by the lever as before explained, being with pauses or intervals between, as experilowered a few inches, when required to throw ence has proved to be the most efficient the valve-plate out of gear, or to allow the valve-plate to pass to the opposite side of the “ Perhaps the best popular illustration of cross-bar, and so become efficient to move the advantage, and in some cases, absolute the vessel in the opposite direction.

necessity, of concentrated power, in the pro“ Fig. 4 is a side view of the propeller pulsion of vessels through water, may be with the valve-plate open, and nearly invisi found in the working of a life boat. These ble, the edge of it only being seen.

boats are fitted with ten or twelve oars, and “ Fig. 5 is a perspeetive view of the pro their service being required in storm and peller.”—pp. 28–30..

tempest, every mechanical means that inge

nuity and physical strength can supply is The “great point" which Mr. Booth little enough for the accomplishment of the considers he has here accomplished " is object. the saving of fuel, and of expense, in the

Imagine a life boat departing for a shipordinary working of the vessel," for,

wreck, three or four miles distant, with a

hurricane blowing, as is too often the case, “ The forward stroke being effected during right on the land. The life boat has ten about one-tenth of the double stroke of the


with as many men to work them. engine, the remaining nine-tenths of each Suppose the continuous plan of working to stroke of the engine having only to bring be attempted, with ten men pulling in quick back at a slow pace the propeller with the succession, the effort, indeed, is almost con.


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