SUBMARINE RAILWAYS-MR. DE LA HAYE'S PLANS. cotton, cloth, or tow. Fig. 8 is a modifica tion of fig. 7, expressly adapted for connecting lengths of pipe, when such lengths have to be fixed vertically, for which reason it is convenient to have the lip or orifice, d, placed in a position different from that adopted in the preceding case. Fig. 9 is a sectional view of a joint piece which is so formed that it may be slipped over the pipes b and c, previously bound with cotton or cloth dipped into cement, and holds them tightly for some distance around the point of contact. The socket ends are next packed with tow, cotton, or other suitable material, dipped into melted cement, and rammed home. Fig. 10 is a joint piece, having within it a stop or check, g, placed about midway, which prevents either of the pipes from being thrust too far while fixing; in other respects the interior is of the same shape as fig. 9. Fig. 11 differs from fig. 9 in having a thread in its interior so as to admit of the use of a screw piece, instead of packing only, the screw piece being attached to the end of the glass pipe; the joint is made with a washer, or the screw piece may be loose, so as to form a kind of stuffing-box, as shown at the end, c. In fig. 12, the pipes b and c have flanges, which serve as a guide to a joint piece, quite plain, the ends of which are caulked as before described. Fig. 13 shows another mode by the aid of metal bolts, washers, and flanges, in addition to those left in the glass pipe; the bolt holes being drilled or made in the metal flanges only. In fig. 14, the male and female screws are made direct in the glass pipes during the operation of moulding, so that one pipe may be screwed into another, and the joint made with a link or washer. In fig. 15, the small screw and flange only are formed in the pipes b and c, and also by blowing and moulding; the rest is of metal. Fig. 16 represents the mode of forming off-sets, when it is found convenient to make them in such way, instead of leaving them in the operation of blowing and moulding by making a suitable hole in the mould.” 325 ject; experience, would of course suggest such improvements as would tend to simplify the work in the details; perhaps, so as to render the construction of submarine railways a work hardly more difficult than a railway on land. I will first allude to the mode of connecting the divisions of the tunnel temporarily under water. Previous to placing the divisions below, I would fasten a bandage or rim of wood outside, at each end; this rim would be 1 foot thick and the same in width, and formed of the shape of the outer circumference of the tunnel. After being fastened by means of bolts, I would nail several layers of tarred canvass on the wood. The divisions being sunk on their position below, end to end, and as close to each other as possible, I would prepare a sheet of lead and one of copper, of a length equal to the outer circumference of the arch; these sheets of metal being laid flat on aloft, the copper over the lead, I would place a sufficient number of pieces of wood across the metal; they should be 1 foot wide and 4 inches thick, and connected by means of hinges; and on each piece of wood I would place a thick plate of wrought-iron. It will be seen that the wood is intended merely as a medium of fastening the different sheets by means of bolts driven through the whole: this covering, which would be sufficiently wide to cover the space between the two divisions, would be thus of an immense strength, and yet could be bent on the arch; when completed, it should be let down on the ends of the two divisions, so as to rest on the rims of wood covered with canvass and tar. The principle will be seen in figure 1. fig. 1. d The proportions of the tunnel are not preserved, in order to show the metal and wood covering on a large scale. A A represent the ends of two divisions; bb. the temporary blockading frames of wood and iron; F, the bed of the sea between the divisions; cc, the wooden bandage or rim; d d, the covering of lead, copper, &c. The covering, d d, being lowered on cc, two divers would descend below, to place it in its position; this, in fact, would be the only work for the divers, as regards connecting the divi sions under water. As soon as the water was pumped from inside the divisions, the pressure without would be so tremendous that the covering, d, would be pressed on c c, as effectually as if it were screwed to the wood. Probably, however, some water would enter the tunnel through the smallest crevices, so that the pumps should be kept at work until the plates e e, were riveted so as to connect permanently the two divisions; the covering d might be afterwards removed, or perhaps it would be better to let it remain, as an additional security. It will be seen that the operation of connecting the divisions will occupy only a short space of time, and that the work left for the divers would be very trifling; several divisions might be connected in one day by having everything requisite in readiness. By these means the submarine operations might be conducted only while the sea was perfectly calm, while the work would be rarely retarded, as during violent storms, the workmen could work inside the tunnel; thus forwarding every department of the work, such as laying down the rails, gas pipes, painting, &c., so that when the last divisions were connected the tunnel would be nearly finished. " Another operation of importance remains to be explained, that is, to sink the divisions near the shore, in the soil, to protect the building from injury during storms. This operation should also be executed rapidly, and with very little work under water. It would of course be impossible to excavate the soil previous to letting the divisions below; the divisions must therefore be sunk first in the earth and the soil excavated afterwards. I presume, that this object can be attained in a very short time, and at a very trifling expense, for gunpowder is considered a very cheap article; although, perhaps, some persons might object to sucha puntity being used for constructing submarine railways, who would not object to a thousand times more being destroyed for a very different purpose: public opinion is, however, rapidly changing, and I presume, that if permission were given by the Government to construct a railway from Dover to Calais the gunpowder would be granted duty free: the object would deserve it, at any rate. The divisions to be sunk in the earth should first be built simply as an arch, having neither floor nor platform outside, as in figure 2. These divisions should fig. 2. be strengthened by means of temporary iron bars, a a, placed at intervals of 10 feet apart; the two ends should then be temporarily blocked up with a framework of wood and iron; they would then be ready to be placed in their positions below, but the soil should be previously prepared for their reception; for this purpose the earth should be bored from diving bells as deep as the height of the tunnel; it would be necessary to bore closely in a soil composed principally of stone, but in light sandy soils it would be sufficient to bore in the two lines where the edges of the tunnel would rest; the powder being rammed down as usual, a wire should lead from each charge to a battery, so as to blast a large extent of earth at once. This operation might be repeated several times, if there was reason to suppose the earth was not sufficiently loosened, which could be ascertained by descending in diving bells, and driving iron bars into the earth at different places. The blasting being completed, the whole length required to sink the tunnel, the divisons should be let down by filling them with water; then a large quantity of iron should be placed on each division; a few hundred pieces of cannon SUBMARINE RAILWAYS MR. DE LA HAYE'S PLANS. would answer the purpose admirably; they might remain on the divisions, or afterwards might be removed, if required for any useful purpose; then the water should be pumped out from each division, and a part of the air removed, to form a partial vacuum; the pressure of air and water, which would be then exerted on the top-would be so tremendous, that they would rapidly sink in the shattered soil; the edges, b b, would cut through the earth as if it were composed of tallow or melted pitch; at least the experiments of Dr. Potts would lead us to suppose so, While this part of the work was proceeding, the tunnel or land should be bored, commencing at a sufficient distance from the shore to have the least possible gradient; it might be arched with brick or stone, or an iron tunnel might be placed inside. The first division of the submarine tunnel being reached, the temporary blockading frame should be removed, and the soil excavated; the earth could be removed with carts placed on the temporary rails of the land tunnel, and drawn by a stationary engine; the excavation would thus proceed much more rapidly than if the earth were raised near the shore as from a well: then the soil having been completely shattered by blasting, could be easily removed from the tunnel, so that each division could be emptied of the earth it contained in a very short space of time, while the work would be attended with no danger whatever. Each division might be sunk to any depth by excavating the soil under the sides; to its weight would then cause it to sink to the required depth; care should of course be taken to let it fall gradually and equally, so as to be level with the en- . trance of the tunnel; the earth being removed, the floor should be fastened to , the division, and the next division excavated as before. It would of course be impossible to sink the tunnel, the whole length in the earth; but I would consider this perfectly useless, for in great depths, the water is so dense, that a tunnel would be as firmly fixed below as if it were imbedded in clay: the tunnel might be sunk in the earth one mile or two at each end of the building; the next division should be only partly sunk; the platform or flange outside being constructed at a few feet from the bottom, as in fig. 3, 327 that is, the flange should be constructed at different heights from the bottom, according to the depth which the division would have to be sunk in the soil, so that as deeper water would be reached, the flange would be at the bottom. Fig. 3 represents the tunnel with stones on the Fig. 3. outer flanges to prevent its rising by its buoyancy; between the stones placed on the flanges, a large quantity of loose stones might be thrown, over which a cement, which would not be injured by water, might be thrown, so as to form a compact mass. There are various kinds of cement which might answer the purpose, such as the patent English puzzuolano, or metallic sand; this would probably prevent the iron wearing, but it would not be necessary to cover the tunnel the whole length, at least, not on first constructing it. Then the iron might be galvanized, which would be an additional protection to the metal. Of course, after being finished, every precautional means would be devised to protect the building, but should it partly wear out in the lapse of time, another tunnel might be placed inside the old one. In wide channels it would be essential to construct the building as strongly as possible, that many years might elapse before it would require repairs; it would be better to build it with two or even three sets of iron plates, leaving a space 3 of 6 inches between each, which might be filled with some light waterproof substance. Such a tunnel would, even in the deepest channel, be as safe as if it were not surrounded by water. And thus, this building would be as a vast hall in which traffic would be continually carried on, while the raging sea above would be threatening to engulph the vessel floating on its bo "I will now explain what steps are necessary to be taken to prove the law of the squares. Suppose ten miles an hour be the maximum from four boilers, and it be required to know what half the quantity of steam will give; close your throttle valve to one-half, the consequence will then be, that the half steam not drawn from the boilers will press on the safety-valve and escape; the velocity obtained will be 8 knots on the principles previously explained: as soon as you have satisfied yourself that half the steam entering the cylinder is attended with this effect, draw half the fires; for, as yet, you are generating steam to waste; but still take care to keep the throttle valve closed to one-half, for otherwise you would soon exhaust all the steam from your boilers: this is often resorted to, when the boilers do not generate steam fast enough to meet the demand of the vessel. Boilers, I cannot help conceiving, ought to be constructed to supply the full demand of cylinders with the most inferior coal, leaving it to the discretion of the commander to reduce his fires as may be necessary. Following this rule, from the above maximum the relative velocity from each boiler stands thus: one boiler, 5 knots 6 fathoms; two boilers, 8 knots; three boilers, 9 knots 2 fathoms; four boilers, 10 knots. "I wish in this place clearly to define the difference of steam used thus, and that from the expansive system. Captain Otway has fallen into error in conceiving both to be attended with a mechanical effect; this is certainly a great mistake; 'steam* wire drawn,' as the former mode is expressed, has no mechanical properties; all the advantage to be derived from it is, that you obtain a higher proportionate velocity for the quantiy of fuel expended; not through any mechanical property in itself, but on the principle that the resistance increases according to the square of the velocity; the pressure is constant and uniform and not expansive. "It is otherwise, however, with the beautiful law that governs the expansive system; here the pressure is not constant and uniform throughout the cylinder. I cannot help conceiving that the great advantage to be derived, from expansive steam is not so clearly understood as it ought to be; for it involves a contradiction of terms to suppose parties to be insensible to their own interests, whe * I have denied any mechanic properties to "wire drawn steam," my to keep the advantage to be derived from "expansive steam" in the foreground; but all power exerted through an agent is strictly speaking mechanical: but this is not the sense in which it is used by Otway (see page 10); he confounds things which in their cause and effect are different. ther they be individuals or communities. Can it be accounted for by stating, that the few fully conversant with the subject will not condescend to make their definitions sufficiently intelligible to meet the understandings of the many, who, after all, as practical men, will have to carry it into execution? Be it as it may, in all the works I have read, much fault is to be found in the manner of bringing this subject under consideration, than which, short of the invention of the engine, there cannot be found one more important. Many are content with giving you the results of their calculations, without troubling themselves to plain how these results were obtained; others furnish us with an illustration in lieu of a definition, as if such would convey any distinct idea; but an illustration neither shows a perfect knowledge of the matter, nor will serve to make your ideas intelligible to another; even when most happy, they convey but imperfect notions; however, it is easier to illustrate than define. If you doubt the correctness of these remarks, only peruse what Captain Williams has written in his lectures on Steam, pages 14 and 32. ex "I also gather from Captain Otway's writings that he has no distinct notions on the subject; for he fairly contradicts himself. "Doctor Lardner seems to have a knowledge of the matter as far as the mechanical effect gained; though it is poorly explained in the 6th edition, in the 7th and last edition his definitions are certainly more intelligible; but is it not surprising that he doubts the applicability of expansive steam to steamers in his 6th edition, and in his 7th, though admitting it is now in use, forms all his calculations with regard to the expenditure of coal as if no such invention had ever been called into existence? Hugo Reid hazards little, and consequently is safe from criticism. How can any man by reading these, arrive at a satisfactory conclusion on a naturally abstruse question, when he finds it engulphed in such a sea of contradiction? "But the Doctor, in denying the law of the squares, robs himself of the landmark that would safely guide him through these troubled waters; he loses his third term in a simple rule of proportion, which third term enabled me to speak with confidence as to the amount of the loss of velocity in proportion to the saving of fuel. "I shall now try to define the expansive system: it is a mechanical property peculiar to steam thus used, by which, though you save one-half that would be required completely to fill the cylinders, you lose less than one-sixth of the effective pressure on the piston. A cubic inch of water will produce a cubic foot of steam: it has then ex RECENT AMERICAN PATENTS. panded into upwards of seventeen hundred times its volume, and exerts a mechanical power equal to raise a ton 1 foot high. But it is a law of steam that its density is always equal to the pressure that it is raised under: remove then half the pressure, and the steam will expand into double the space, exerting a mechanical power equal to support half the original pressure. Place two tons upon the piston, and the steam will then only occupy the space of 6 inches; that being in strict accordance with the above named law. (To be concluded in our next.) RECENT AMERICAN PATENTS. [Selected and abridged from Mr. Keller's Reports in the Franklin Journal.] · AN IMPROVEMENT IN DOOR-LATCHES. James M. Hoggan.-This is for an improvement on that kind of mortise latch in which the bolt is thrown back by turning the knobs either to the right or left, the projections or levers on the spindle being located within an opening in the body of the bolt, and acting on the back face thereof. The alleged objection to the old plan, which it is the object of the present modification to remove, is the small extent of motion given to the bolt, or if not this, the great width required to be given to the opening, in the bolt to receive levers or projections on the spindle of sufficient length to give the required motion to the bolt. To remedy this defect, four cogs are made on the spindle above, two above and two below, and one above and one below in the space or opening in the bolt. The first cog above and below on the spindle are on the same plane, and act against the back face of the opening in the bolt, and the other two are on a plane further back and act on the cogs of the bolt. This arrangement of the cogs is necessary to admit of pushing back the bolt by turning the knobs in either direction; for when the upper cogs are in action, the lower cogs pass by each other, and vice versa, which would not be the case if all the cogs were on the same plane. Another improvement is for adopting the spindle to doors of various thicknesses, by tapping the spindle for the reception of the knobs, which screw on, and providing a slot at each end, instead of a hole, for the securing pin. 285 of the box are let into grooves in the follower or platen of the press, and work up and down with it, and at the end of the operation they are lifted out of these grooves and liberated by two short levers that strike against projections on the frame-these levers are designated in the claim by the letter z. The lower edges of the sides of the box are jointed to the frame, and, when closed, are held in place by two bars, which are thrown up towards the end of the operation, by pins connected and moving with the platen. Claim.-"What I claim as my invention, is-1st. The combination of the inclined parallel levers with the horizontal carriage and rollers, arranged and operated in the manner and for the purpose set forth. 2nd. The arrangement of the ends d of the box grooves in the platen, so as to rise and fall with the platen, and be liberated from it at the termination of the pressing. 3rd. The combination of the levers z with the platen, arranged and operated in the manner and for the purpose above set forth. 4th. The manner of disengaging the bars from the box, by means of the pins upon the ascending ends of the box, in order to throw open the sides of the box, to tie and remove the bale." IMPROVEMENTS IN THE TIDE MILL. JOHN GERARD Ross.-The wheel is placed in a race, at one end of which there is a tide gate hinged to a wall beyond the end of the race and shutting against either side of the race; and at the other end of the race there are two current gates, one termed the "inner current gate," and the other the "outer current gate;" these are hinged to the ends of the race-way wall and shut against a pier placed beyond the end, and in a line with the middle of the width of the race-way. The current in passing along opens the "current gate," and after acting on the wheel passes out through the "outer current gate," and on the return, tide the pressure of water closes this "outer current gate,' " which causes the current to pass round to that side of the tide gate opposite to that at which it entered on the rise of the tide, throws it against the opposite side of the race-way, acts on the same side of the wheel as on the rise of the tide and passes out through the "inner current gate." The dam walls are formed with pits open at the sides for the free ingress and egress of the water to act on floating caissons which sustain the wheel and always keep it at the required elevation. The shaft of the wheel (or wheels) is connected with the frame work of the mill by bars radiating from the axis of a cog-wheel, into which mash the cogs of the master wheel. Claim.-"First. I claim as new, and of |