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circumstances, the inferior column may be prolonged at will. Also, the action of the water acts simultaneously by the pressure of the inferior column, and from this combination the inventor has called his machine the double-acting turbine. This system of construction offers advantages which will be appreciated by those who are aware of the great expense of mill work for foundations.
It is sufficient for these turbines to place below the surface of the lower level the conduit for conveying the descending current, with a regulating sluice at the end, and to fix the stay block which receives the arbor, or point, of the shaft in the interior of the tube at the most convenient height, taken between the surfaces of the two levels. In this manner it is always easy instantaneously to run the wheel dry, and so keep it underhand. The turbine is also provided with a sluice for its supply, and when it is required to be put in motion it is opened to give passage to the water, and the receiver is first allowed to be filled completely up to above the turbine, when the discharge sluice
is opened, and the water allowed to flow out in quantity and relation to that of supply, so that the column within the receiver is always kept to one level.
Reference to the Engravings.-Fig. 1, vertical section of the turbine through A B, of fig. 2. Fig. 2, transverse elevation taken through C D, of fig. 1. Fig. 3, horizontal section through E F, of fig. 1. The same letters are used for the same parts in each of the three figures.
a, water-wheel called the turbine; b, shaft of the turbine; c, block, or step, supporting the axis b; d, guide, or fixed turbine, supplied with helical curves which serve to give to the fluid vein the desired direction; e, case of the turbine; f, upper channel; g, lower channel; h, sluice of the canal f, to regulate the flow to the turbine; i, sluice of the canal g; k, float; 7, upper collar of the shaft b; m, support of the collar; n, bevel wheels and shaft of transmission, supported by another collar, which, like the former, is secured to the support m.
Fig. I, represents the water of the upper channel, in communication with the lower channel g, passing through the guide d, the turbine a, and the case e, which may properly be called the channel of junction. It is by passing through the turbine a, that the water impresses on it a rotary movement in the direction indicated by the arrow a', figure 3, a direction which would be inverse if the guides, as well as the vanes, of the turbine were inclined in the opposite direction.
Passot's Turbine.-M. Passot also exhibited one of his turbines, (see figures 4 and 5,) the construction of which is founded upon using reacting wheels, and produced by the effect of centrifugal force. They are composed of cylindrical vessels fixed to vertical arbors, and supplied at the circumference with orifices intended for the introduction, or ejection, of the water. The modification which M. Passot has introduced into the old reacting wheels, and which he claims as his invention, consists of having suppressed, or got rid of, the internal partitions, and reduced the old wheels to their only true essential elements-a motive cylinder to contain the motive fluid, with surfaces to receive its action, and corresponding orifices for discharge. The surfaces and the orifices are exactly included between two concentric circumferences, that is to say, that he carefully retrenches all other surface, or projection, capable of impressing the water with the angular movement of the wheel before having reached the parts destined to receive its action, as well as the orifices of discharge. "I form the new wheel," says M. Passot, "simply by placing either in the interior, or exterior, of a cylindrical drum, according as I want the pressure of the fluid to be exerted on the interior, or exterior, curved vanes in the arc of a circle, such as a b c d, figures 6 and 7, then I make orifices of discharge, by removing from these vanes and from the cylinder the part in form of a wedge, a b d, and the motion is effected by virtue of the pressure on the faces c d, c' d', c" d".
"While the machine is very simple, its properties are very remarkable. When the wheel turns without load, or work, under a given difference of level, or fall, its vanes take exactly the theoretical velo
city due to the fall.
It is no longer the same when in any manner the form of the new wheel is altered so as to approach those formerly
known; all partitions, projections, and asperities which are either
within, or without, two concentric circumferences, considerably diminish the theoretic velocity of rotation due to the fall, on account of the continual shock of these bodies in motion against the water in repose. Then it is not surprizing if the useful effect of reacting wheels when experimented upon has never risen above fifty per cent., that is to say, about the rate of breast wheels of the usual varieties.
"The expenditure of water in figure 7, with the internal action, is sensibly independent of the greater or less reaction of the wheel. In figure 6, with external action, this cannot take place on account of the counter pressure arising from the formation of an eddy in the interior; but this counter pressure is, however, much less than might be supposed. I have demonstrated that when a fluid forms an eddy in the interior of a cylinder, the effects of the centrifugal force show themselves differently according to the different inclinations of the projections, or orifices, made on the circumference.
"In No. 1, the orifices are disposed in the direction in which the centrifugal force can least influence the expenditure of water. Thus the coefficient of theoretical expenditure due to the work, during the experiments on the turbine, which I constructed at Bourges, has been found very little different from that which agrees with the openings of ordinary sluices disposed so as to avoid contraction on three of the sides. The wheel which turned in work, with about half the velocity due to the fall, and the coefficient was 0.70 to 0.79."
Explanation of the engravings of Passot's turbine, a b c, figure 5, plan of the wheel. A B C, fixed base of cast-iron. MN, cover acting as a sluice to regulate the expenditure of water. pq, block of wood carrying the step of the arbor, or shaft. EV, male and female screw, serving to regulate the cover by means of the rod T t, passing through the hollow shaft. L l, lever to raise the whole motive system by means of the pivot.
M. Poncelet, adopting an arrangement the reverse of that of M. Fourneyron, has proposed a system of turbines of the nature of the horizontal wheels used in the centre and south of France. The water enters by a spout placed on the outside, stretches the vanes, and is discharged by two openings made towards the centre. M. Cardelhac has constructed at Toulouse turbines on this plan, and Messrs. Mellet, and Sarrus, of Lodeve, have exhibited one with the same arrangement. The principal part of their turbines consists in a case of particular form, provided with three openings, of which one is for the water to enter, and the two others to allow it to escape after its action on the wheel. In consequence of the spiral form of this casing, the water arrives on the wheel placed in the interior without any shock, and with a velocity due to half the height of the fall. Each of these veins, or streams, of water acts at the same distance from the axis, as if it were isolated and independent of the other; its velocity is transformed into pressure by insensible degrees, and without any loss of power. Messrs. Mellet and Sarrus have already put up several of these turbines in the south of France with good results. They come cheap, one for an ordinary grist-mill costs 40%., one of 12 or 20 horse power, well finished, and of good material 1207.
There was at the exposition another hydraulic machine, which the maker, M. de Lamolere, calls a piston wheel. This machine receives water like a breast wheel. The water brought by means of a plunging fan, falls into a bucket, where it stretches a wooden valve, fitted with leather. It passes through this valve, which is followed by a second also. These successive valves turn horizontal shafts, which then give movement to the factory. Civ. Eng. & Arc. Journ.
List of American Patents which issued in the month of August, 1844, with Remarks and Exemplifications. By CHARLES M. KELLER, Examiner of Patents.
1. For improvements in Tanneries, and the Handling of Hides; Wm. Brown, Manchester, Carroll county, Maryland, August 1.
Claim. "What I claim as my invention, is constructing the leaches and vats so that the liquors pass through the top strainer of one leach into the bottom of the next throughout the circuit, or direct to the pump, and are returned from the vats, after being heated, to the bottom of the leaches, and in combination there with the arrangement of tanks, stocks, and spiggots, by which I effect these objects. I likewise claim the revolving rollers of the tanning and liming frames for accommodating the hooks to the shrinking of the hides, and the manner in which I arrange the two shafts, connected and operating as described, for working the tanning and liming frames to which the hides are suspended, and in combination the reels and shafts for handling, baiting, and washing; likewise the manner in which I arrange the railroad and car, with respect to the mill, and the leaches by which the bark is conveyed direct to the leaches, and deposited therein."
The leaches are provided with perforated false bottoms, on which the hides are placed, so that the liquor can be admitted from below by means clearly indicated in the claim. They also communicate by means of hollow trunks, with the vats, &c. The tanning and liming frames are provided with rollers armed with teeth, to which the hides are attached, and which yield to the shrinking. These frames are hung to arms projecting from shafts so linked together, and connected with a crank shaft that, as one descends the other rises, and vice versa. The reels to which the hides are suspended in the vats are operated by hands extending from a rocking shaft, also connected with a crank shaft, by which the handling, baiting, and washing are effected. Above the four leaches, which are arranged around the shaft of the bark-mill, there is a circular railway with a car to receive and convey the ground bark to any of the leaches, the car being provided with a drop bottom, and a catch, by which it can be attached to, or detached from, an arm on the mill shaft.