HOLEBROOK'S PATENT PADDLE

WHEEL.

Amongst the numerous patents which have lately been obtained for improvements, or rather alterations, in paddlewheels, and the modes of propelling steam-vessels, the specifications of which appear on the rolls of the Court of Chancery, there is not one which appears to have been more the result of close study and calculation than that patented by Mr. J. P. Holebrook. At first sight, or even upon a cursory examination, it would appear to be very similar to Morgan's, Galloway's, and Seaward's paddles, and, by many, would as such be instantly dismissed from the mind, as a most glaring plagiarism. On examination, however, into the details, and careful tracing of the working of the radial rods, arms, and paddles, through their various positions, it will be seen that there is considerable difference, -and that, in that difference, great superiority lies. That it is a modification of the same principle as that upon which Galloway's or Morgan's wheel is founded, no one can deny; but Mr. Holebrook is as free to come into the field, or rather on to the water, with his arrangement of this principle, as Mr. Morgan, or the many others who before and since Mr. Galloway's patent essayed to improve the common wheel, by applying moveable paddles, guided into their several positions by an eccentric or crank.

place at parts at which the employment of power is attended with greater beneficial effect. It is demonstrable that such greater effect can be produced by a properly propor tioned combination, in which the paddles should enter and leave the water at angles, obtained by positions between radial and vertical ones, agreeably to circumstances, than by paddles fixed radially, as in the common paddle-wheel; but it is essentially necessary that the machinery in use should be of such a construction as to render the employment of it prudent, on the score of strength and lightness, for, otherwise, it will be a matter generally of little doubt that the simpler and stronger machinery will be preferred, ferred, even with a certain persuasion of a loss of power, to the more complex and less secure instrument although the employment of it be as certainly attended with increased effect but, when the parts of such machinery are put together with proper attention to strength and lightness, and the employment of it attended with increased effect, it will scarcely be wise to resist its use on the score of its parts being moveable, and, in consequence, more complicated, because the employment of more complex, and, at the same time, more economical machinery, for the attainment of a desired end, is always a proof of a greater approach to perfection in the means of attaining an object in view. The steam-engine, in its most economical, and in its more simple, form, is a proof of this assertion. Indeed, it may generally be considered that complexity of machinery, while it is attended with increased effect, is no bar to its employment, provided there be no objection to the machinery in point of strength, security, or too great complexity.

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"In his improved method of propelling vessels, the inventor has carefully studied to obtain, by the application of a new plan of

"It has been suggested, as regards the carrying on of steam navigation by sea, and when the immersion of the propelling apparatus necessarily must be great, that it would be desirable that the paddles should enter and leave the water at angles, other than those obtained by radial positions of the paddles, in order that less power may be consumed by the paddles when entering and leaving the water. and a greater proportional beneficial return be obtained even for the diminished power consumed at such points by the paddles, and in order, further, that a greater consumption of power may take

paddles as are considered desirable, with all due attention to strength and lightness, and within the space usually allowed. He particularly calls attention to the construction of the skeleton of his paddle-wheel, which, though more complex than the framing of a common paddle-wheel, can scarcely be said to be less strong. He also desires an attentive consideration should be given to the construction of his paddles, by which, though they may be guided by parts near their extremities, it will be seen that it is scarcely possible to conceive a case in which they can be twisted and put out of form.

"Of the skeleton of this paddle-wheel, it may further be said that, from its peculiar form, it can, in case of accident, by the addition of common float-boards, be readily converted into a common paddle-wheel;

and, by this, it will be perceived that, in cases of accident to its moveable parts, it may be made equally effective with the common paddle-wheel, while, until such cases of accident occur, the extra benefit of its peculiar positions of paddles may be obtained. That accidents such as those to which allusion has just been made, never have happened with wheels properly constructed with moveable paddles, has been proved by the employment of such wheels, for some years past, in the government navy.

We shall now proceed to describe Mr. Holebrook's wheel, and in so doing, we cannot convey a clearer idea of the plan than by quoting his specification.

"Figure 1 is a side view of a wheel constructed on this plan; and fig. 2 a sectional view, showing more clearly the essențial parts of the wheel. The wheel consists of five principal parts, with their connections and appendages; namely, an octagonal framework, in two parallel pieces; the paddles between these frames; a guide-wheel, to give the desired position to the paddles; a crank, to which the octagonal framework and guide-wheel are connected in common; and what I call a star-wheel, which transmits the power directly, from the end of the paddle-wheel shaft, to the outer circle of the paddle-wheel. a a are the arms of the outer circle of the paddle-wheel, terminating, on the outer side, in the octagonal framework, and, on the inner, in a nave, which turns loosely on a part of the crank before mentioned. bed is a bar, which passes from one part of the octagonal framework to another, intersecting two of the arms a a between the points b and d. e e are the arms of the guide-wheel, which are connected, on the inner side, with the crank before mentioned, and project, on the outer side, a little beyond its octagonal frame.

"The centre of the guide-wheel is placed a little above the centre of the paddle-wheel. The paddle-wheel and the guide wheel are connected together by means of two metal straps, moving pon four pivots; two of which are fixed in the guide-wheel, at the points f and g; and two at the points h and i, of the bar b c d. The object of the bar b c d being to obtain the two positions h and i for two of the pivots of these straps; it is so placed, in the paddle-wheel, that if a circle were drawn from the centre of the paddle-wheel, of the same size as a circle drawn from the centre of the guide-wheel, passing through the points ƒ and g of the guide-wheel, and two radii drawn from the centre of the paddle-wheel, intermediately between the radii of the paddle-wheel, between

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which radii the parts h and i are placed, the points of intersection, of the circle and these two radii, would be h and i. From the angles of the octagonal framings and the extremities of the arms of the paddle-wheel, pass eight strong rods, pppp, which brace together the inward and outward circles of the paddle-wheel. The paddles jj, with the stems fixed to them, are placed upon these rods, and connected with the guide-wheel by means of the rods, which I call guiderods, one end of which is attached by means of pins, on which they turn, to the projecting ends of the arms e of the guidewheel, and the other end works upon pins placed at the extremities of the stems of the paddles. Each paddle consists of a plate of iron, an iron half-pipe with almost entirely closed ends, and three iron stems. A superficial view of one of these paddles complete, given separately in fig. 5, and, an end view, in fig. 6. A superficial view of the half-pipe is also given separately in fig. 7, and an end view in fig. 8. The half-pipe, it will be observed, is placed by its edges against the iron plate, and upon this halfpipe and plate are placed the three stems; the whole being firmly fastened together.

"From the extremity u of an arm of the guide-wheel, a guide-rod proceeds to a stem of the uppermost paddle, fig. 2, while, from another extremity v of another arm of the guide-wheel, a guide-rod proceeds to the stem of the lowermost paddle; both stems having holes in them for pins for the connection of their respective guide-rods. Any direction given to either of these guided stems will be mainly transmitted, by the half-pipe, to the other stems and the other parts of the paddle; and, thus, any twisting of the paddle is scarcely possible of occurrence. It is not necessary to have three stems to a paddle, nor, is it absolutely necessary, to have the paddle constructed of iron, as I have supposed it to be; because it may be made of wood and iron in various ways; but the method I have described is one which I think to be, at once, useful and strong. From what I have stated, it will have been seen, that the paddle-wheel and the guidewheel are attached and made to revolve together, upon the principle of a well known method, namely, by means of straps or cranks, the distance between whose working points is equal to the amount of the concentricity of motion of the paddle-wheel and guide-wheel, and whose same points are in a direction parallel to the direction of the centres of the paddle and guide-wheels. Every paddle, in the course of one revolution of the wheel assumes in turn each of the positions which the different paddles exhibit in fig. 1, or other positions corresponding therewith.

"In the sectional view, fig. 2, n o represents part of the paddle-wheel shaft; a a a a the arms of the paddle-wheel connected together at their extremities by means of the rods p p pp, upon which the paddles, j j, turn; the inward arms, a a, of the paddlewheel, terminating inwards in a nave, firmly fixed to the paddle-wheel-shaft; and the outward arms, a a, of the paddle-wheel, terminating inwards, in a nave which revolves loosely upon the lower part of the crank Im. Hitherto, the only connections I have shown between the outer and inner circles of the paddle-wheel are the rods pppp; but, in q r s t, fig. 2, and shown, separately, in figs. 3 and 4, is represented the starwheel before mentioned, which I have introduced for the purpose of further connecting the outer circle with the paddle-wheel shaft.

"I call it a star-wheel because it resembles in form a wheel without a periphery or bounding lines. It is firmly attached, by a nave to the extremity of the paddle-wheel shaft, and, by the extremities of its arms, (which are made of a bent shape for the purpose,) to parts of the arms, a a, of the the outer circle of the paddle-wheel. By means of this star-wheel the outer circle of the paddle-wheel is more directly moved, by the paddle-wheel shaft, than by means of the rods p P P P, upon which the paddles move. It should properly be stated, in this place, of this starwheel, that the peculiar bent form given to it, in fig. 2, is not its only form; because, according to circumstances, it may be bent differently, and may be superseded by a wheel with a rim; the arms of which wheel need not be bent, but the extremities of which arms may be attached, by means of rods, connecting other formed framings of the paddle-wheel, and this then modified apparatus together; but, I would here observe, that the form which I have given to this apparatus in fig. 2, is that which I consider generally to be most desirable. It should be here noticed, that this apparatus is not seen in fig. 1; because, being placed behind the paddle-wheel, and its arms coinciding in direction with parts of the arms of the paddle-wheel, shown in that figure, it could not be exhibited in such a view of the wheel as given in that figure. In a paddle-wheel, such as is represented in figs. 1 and 2, the measure of the eccentricity of the combination is equal to about one-half of the distance, between the centre of the stem of a paddle and the point at which the stem is guided; but, it is hardly necessary to observe, that this measure of eccentricity may be increased; and that, in proportion as it is increased, the paddles, which

are at the bottom of the wheel, will assume positions more nearly vertical; and vice versa. The converse of this proposition must be equally evident; namely, that, in proportion as the distance between the two before named points of the stem of a paddle is diminished, the paddles will also assume positions more nearly vertical ones; and vice versa. From fig. 1, it will be perceived, that the arms of the guide-wheel, upon which the two lowest guide-rods are placed, are equally distant from the lowest arm of the paddle-wheel; and this will be found to constitute an important novelty in my plan of construction; for, it is by this, or some like relative position of these two parts, that I ain enabled to obtain such positions of the paddles as are shown in the figure. I have used a crank, as a point upon which the guide-wheel may revolve, and, I have placed the guide-wheel within the paddle-wheel, but it is not absolutely necessary, either, that the crank should be used, or, the guidewheel so placed; because, a guide-wheel, upon a large eccentric centre might be used, and, the guide-wheel might be placed outside of, and, on either side of, the paddlewheel, though not, in my judgment, to so much advantage.

The principal points which distinguish Mr. Holebrook's from Morgan's wheel, are very clearly set forth in the following communication which we have received from Mr. Holebrook :

"The objects sought in the construction of my paddle-wheel, are precisely similar to those obtained in that modification known as Morgan's paddle-wheel; these objects being a more economical application of power with less swell and less vibration than is attained by the use of the common paddle-wheel. It would be wide of my present purpose to enter upon an illustration and demonstration of the advantages resulting from the attainment of these objects, inasmuch as these have been so elaborately treated upon in the late splendid edition of "Tredgold on the Steam-Engine," &c.: It will, therefore, perhaps be deemed allowable that these advantages should be considered as settled. This being granted, I shall proceed to point out the improvements in my wheel upon Morgan's. The first improvement I shall notice, and, indeed, the most important one, is that in the construction of the framing of the paddle-wheel. In Morgan's wheel it will be recollected, by those who have a knowledge of it, that the power is transmitted, di

rectly to the inner framing of the wheel, from the end of the paddle-wheel shaft ; which shaft terminates with the inner framing, leaving the power, which is necessary to turn the outer framing of the wheel, to be transmitted through the ties of the wheel alone. Now, then this mode of transmitting the power, scarcely any method can be be more objectionable; for, it is clear, that the resistance offered to the passage of a paddle, operates as much upon the outer, as upon the inner framing of the paddlewheel; while the outer framing derives, under this plan, all its strength from the ties which connect it with the inner framing; and, as a consequence, this inner framing must either be made much stronger than the outer framing, or the outer framing must be much less capable of bearing a resistance than the inner one. It is true, that as much ingenuity has been called into exertion, in endeavours to obtain, by a good disposition of the ties of the wheel, as much strength, with as little expenditure of metal, as, probably, the plan of transmitting the power will admit. In my wheel, it will be perceived, that the shaft is continued nearly to the outer framing of the paddle-wheel; and that, then the extremity of the shaft is directly connected with the outer framing by means of an apparatus, which I have denominated a "star-wheel," i. e., "a wheel without a periphery or bounding lines." By this means, I dispense with a complicated system of ties, and obtain what, mechanically considered, is a far stronger form of wheel: in fact, it needs but little examination to perceive that, as far as the framing of the paddle-wheel is concerned, it is scarcely, mathematically considered, less strong than the framing of a common paddle-wheel. That this improved form of framing is an improvement upon the framing of Morgan's wheel, I think very few will deny; and also that, considering that my star-wheel performs the part of the complicated ties of Morgan's wheel, my construction is far less expensive of manufacture.

"The next improvement I will notice, is that resulting from the absence of bent stems. The mode of actuating the paddles in my wheel being essentially different from that of Morgan's wheel, I am enabled to dispense with the bent

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stems of that modification; I mean those arms projecting at nearly right angles from the surfaces of the paddles, by which the paddles are guided in Morgan's wheel. The absence of these stems in my wheel would necessarily make its cost less than that of Morgan's, while it also obviates a chance of accident from the breaking of these stems. In my wheel, it will be perceived, that the paddles are guided by the extremities of those stems of the paddles which are employed for the purpose of strengthening them.

"The last improvement which it may be worth while, now, to notice, is another dependent upon the difference of my mode of guiding the paddles, as compared with that pursued in Morgan's wheel. In the passage of a paddle through a revolution, it will be seen, that, in Morgan's wheel, in consequence of the guide-rod of a paddle approaching at times the centre of the paddle, it comes within its sphere of action; it, therefore, becomes necessary to cut a slit in the paddle, in order to allow of the proper playing of the guiderod. Taking this into consideration, I think the absence in my wheel of the necessity for thus slitting every paddle, will be considered as another improvement upon Morgan's combination.

"Having now disposed of the improvements in my wheel upon Morgan's, I propose to make a few observations upon what may seem a similarity, resulting from its being a new application of the same principle of actuating the padIdles; I mean, that, because I obtain in my wheel the same positions, or nearly so, that Morgan does in his, it may be inferred, that, while improving the construction of Morgan's wheel, have been essentially applying a method of guiding the paddles which belongs of right to Mr. Morgan: that I have not thus applied his method it will be my endeavour now to prove. In order to this proof, I shall notice the points of similarity, and points of difference, between mine and Mr. Morgan's wheels.

"The most striking point of resemblance between the two wheels is that of the same positions of the paddles, or nearly so, being attainable in both: in respect of this, I have to say, that I am not aware that Mr. Morgan claims the