t

AC

A

replaced, and managed.

It has been said before, and cannot be too often repeated here, that heat is the source of power. And it would be absurd to suppose that any intelligent person considered that the machinery, or any part of it, from the paddle-floats of a steam-boat, back to the boiler, really augments the power which proceeds through the boiler, and along the steam-pipe. The power, i. e. the combined mechanical agency of elasticity and momentum of which the steam consists, is within the steam-pipe. The engine, machinery, and paddles only offer the means of bringing that power to operate upon the water, and urge the ship in her

course.

The proposers of hot-air engines have taken the steam-engine, subsequent to the discoveries of Newcomen, as their model, whilst they should have reverted at once to the engines of Savery and of Papin. They should be referred to the Marquis of Worcester's scantlings, and even to the smokejack of Hieronymus Cardan.

The Marquis of Worcester employed the pressure of steam to act at once and directly upon the water which he desired to put into motion. Savery, also, used steam in direct connexion with the water. Denis Papin improved on these by interposing a loose floating piston between the steam and the water to be moved.

Now, had any one of these latter used, instead of steam, the hot products of combustion from a close furnace, the steamengine would not now be the only available inanimate artificial power in use for such purposes as raising water, and for locomotion and navigation.

1st. That heat is the source of power in all our artificial motive agents.

2nd. That machinery does not increase the power of any machine, but only transforms or transfers the motion.

3rd. That the expansion arising from a given amount of heat applied to gaseous bodies is much greater than from the same amount of heat when applied to liquid bodies..

The first two propositions will be admitted as correct by any tyro. We need not stop to examine them. Our discussion of the third proposition shall be as nearly as possible in the words of the best chemical authorities.

"It may be laid down as a general rule, to which there is no known exception, that every addition or abstraction of caloric makes a corresponding change in the bulk of the body, which has been subjected to the alteration in the quantity of its heat."*

From the experiments of Dalton, Gay Lussac, and others, it is well established that all gaseous bodies whatever, similarly circumstanced, undergo the same expansion by the same increments of heat; and Dr. Ure adds his testimony that "Expansions of aëriform bodies are proportionate to the augmentation of temperature ;" and in the words of Dr. Thomson, the expansion and contraction differ exceedingly in different bodies. "In general, the expansion of gaseous bodies is greatest of all.”

We proceed now to give the description of the Fumific Impeller, as it is contained in Mr. Gordon's specification:

Fig. 1 is a sectional elevation of such an
Thomson's Chemistry.

apparatus, as will explain the nature and action of the Fumific Impeller. A, is a fire-grate inclosed in a strong close furnace B B. There is on the top of this close-chamber B, a bonnet-valve Č; and at the bottom there is another bonnet-valve C'.*

The valves being open for the purpose of laying and lighting the fire, which may be of coal, wood, coke, charcoal, peat, or of any other fuel: and the fire having attained a good state of combustion, the valves C and C' are well luted and closed tightly on their respective openings.

D is a blower, which supplies atmospheric air to support the combustion in the close furnace. The air being directed by means of the valve E, so that it shall pass through the pipe F or the pipe G; the former conducting it under or up through the fire, and the latter to the top and over the fire; thus the exact quantity to pass through or close to the fire may be regulated for consuming a quantity of fuel sufficient for producing the hot products required for the fumific influence; and thus the speed and power of the Fumific Impeller may be increased or diminished. H is a pipe leading off from the top of the close furnace, by which the hot sëriform matters generated by the process of combustion are carried off to be applied in the manner which shall be explained more fully below; and these hot aëriform products of combustion are intermingled usually with some dust, ashes, and other solid matters, but which do not interrupt the dynamic action of the gaseous body. Air, it is well known, will, when heated by one degree of Fahrenheit, expand about 4th part, and continue to expand so as to have its expansive force or tendency increased in about the same proportion for every additional degree of temperature.* It

B the inside of this close furnace is constructed of fire-clay, or fire-tile, and the external shell is formed of wrought-iron, of sufficient strength and sufficiently tight to resist the pressure from within. It might be made altogether of iron; but if the iron were not protected by some inner casing, it would not withstand for any great length of time the high temperature to which it must necessarily be ex'posed.

C C', these valves are kept tight upon their seats by means of the usual springs or weights, and not only serve for closing their respective apertures, but they are arranged so that they can blow open as safetyvalves, when the pressure from within shall exceed the power of the springs or weights employed to keep them close.

T is a pipe fitted in the close furnace, which, being provided with a talc-sight, enables the attendant to see the state of the fire."

↑ Dalton determined that 100 parts of air being heated from 55° to 312°, expanded to 132,5 parts; this gives us an expansion of parts for 1° Fahr. Gay Lussac determined the expansion to be; and although in Sir David Brewster's edition of

follows that if the temperature of a permanently elastic aëriform body be augmented by about 480°, the bulk of that body will be doubled, or if it be retained within the space it originally occupied, its presure will be doubled. It is by availing myself of this well-known law of expansion by heat and the new arrangement of particles in the close furnace, that I can obtain a rush of power from the furnace along the pipe H, analogous to the rush of steam from a steamengine boiler along the steam-pipe to the engine,-equal to it in pressure, power and constancy, and, when required, at much greater velocity.

The air driven into B for support of combustion must, of course, be driven in against the pressure due to the heat of the products of combustion; for, supposing the latter are at the temperature of about 500°, there will be an atmosphere of surplus pressure against the blower; and it will be found that the blower, to do its work, will require a power of half the power generated by the heat. The manner in which this blower is worked, and also the manner of starting the engine, are shown below.

It has been before shown, that the power of a steam-engine is from the fire" through the boiler and along the steam-pipe; that the power-i. e. the combined mechanical agency of elasticity and momentum, of which the steam consists-is within the steam-pipe." Now, in the Fumific Impeller, the power-i.e. the combined mechanical agency of elasticity and momentum-is in the hot products of combustion themselves, which are in the pipe H.

In a steam-engine, the power of heat is necessarily transmitted through a costly and elegant system of machinery to act upon the bodies, which it moves or which it moves upon; the steam being carefully prevented from contact with any body but its own engine. In the Fumific Impeller, the power of heat is brought without the aid of any transmitting machinery, to act directly and at once upon the body or bodies to be put in motion, or on the medium or media in, or on, or through which the ship, or machine, or carriage, is to be moved or impelled.

A stream or streams of the hot products of combustion are discharged under water backwards, and the vessel moves forward, or they are discharged forward, and the ship is moved backward. It is a case of recoil analogous to that which takes place in a rocket occasioning its flight, but differing from that

Robinson's philosophy, 24, or about 17, is stated, we find Dr. Ure, in his 'Dictionary of Arts (artic.eExpansion,') states that all gases expand 4 for each degree of Fahrenheit.

of the deadly missile, in being manageable and safe.

Let us now see how a ship may be fitted and actuated by the Fumific Impeller.

Fig. 2 is a longitudinal view of the midships and after-part of the ship, with the midship part shown in section. Fig. 3 is a plan of fig. 2, and fig. 4 is a cross-section of the same.

The functions, actions, and mutual relations of the fires; the close furnaces, B B; the valves, CC' CC'; the blowers, DD; the cocks or valves, EE; the pipes, F F and G G; and the pipes H H, which lead off the power from the close furnaces, need not be described here. They will be understood to be a double arrangement of what has just been shown and explained in fig. 1.

The products of combustion intermingled with any dust, ashes, or other solid matters, (even cinders and clinkers,) are caused to rush along the pipe H on each side of the ship, and through one or other of the valves U or V directly into the water. If, on the larboard side, the valve U be opened, and the valve V be shut, while the valve U on the starboard side is open, and the valve V shut, the products of combustion must then rush out at the discharge pipes, W W, and overcome the inertia of the ship, and the continuous flow of power from W continues the onward movement of the ship.

The ship having been put into motion, a fan or screw X in the dead-wood of the ship is, by the motion of the ship, caused to revolve, and its shaft Y gives motion to the tight-blowers or air pumps at DD.

As the valves U U may be used for impelling the ship forward, so the valves V V may be employed to back the ship, and the valve U on one side of the ship, and the valve V on the other side of the ship, may be employed to put the ship about.

The pipes branching from the valves U and V may be kept inside of the ship, and made to terminate and discharge the power when the moulding of the bottom bilges or other submerged part of the ship may intersect them. Z Z is a folding chimney with a sliding part at the lower end for carrying away the smoke and vapour when the valves C and C' are opened. Fig. 5 shows a plan of the interior of the discharge pipes leading from the valves U and V. The curved partitions t t are useful to direct the current forward or aft as may be required.

To put the impeller in motion a few cubic inches of water are injected, by a small pump or hopper, into the fire, which water flashing into an aëriform state (partially or wholly decomposed) gives the first stroke or strokes to the Impeller. Or, instead of

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water, a solution of nitre, which will also be found very useful in getting the fire into greater activity.

The combustion of the fuel may be accelerated, and also additional heat be obtained, by injecting into the closed furnace from time to time, by means of the blower D or any other blower, some coal-dust, or powdered rosin, or other pulverised combustible or supporter of combustion. But whether such materials are blown in singly or together, they should be introduced into a cold part of the blast pipe, blown or dropped upon the fire, not passed up through

it.

Of these auxiliary materials coal-dust will, perhaps, be found the best to employ, for it can be readily obtained; and, as it inflames rapidly, there is, consequently, a rapid augmentation of the volume of heated air and vapours.

Sometimes these auxiliary materials may be forced into the close furnace by means of a hopper, which may be kept air-tight by a double mouth-piece, or the hopper may deliver the said auxiliary materials, by means of a cock half perforated, or a fluted roller. One or more short tubes T fixed in the upper part of each furnace (with eyepieces of talc, for the purpose of keeping in the pressure) serve to sight the condition of the fire.

The bonnets or valves C and C' can be opened as often as necessary in order to clear the fire-grate or to supply fresh fuel, and they are rendered tight by means of asbestos and white or red lead as a luting, or by means of other good luting.

Sometimes a close hopper or hoppers with double mouth-piece, may be adopted for supplying the whole of the fuel to the fire, and sometimes it is advantageous to supply through such hopper a mixture of coals and water.

The proportions, between the area of the fire-grate or fire-space and the area of the pipe H to be preferred, are about the proportions at present adopted by makers of marine steam-engines in their fire-grates and main steam-pipes. But the Fumific Impeller may be worked with a smaller proportion of fire-grate; because, not being delayed by the process of transmission of heat through metal, (as is the case in a steamboiler,) but being as rapid in the generation of power, as is the appropriation by fire of oxygen from the air blown in, there can be no other limit set to its speed.

It will now be easily seen how a locomotive engine may be impelled by this motive agent.

Figs. 6, 7, and 8, exhibit sketches of an application of my Fumific Impeller to locomotive or railroad purposes; fig. 7 being a

longitudinal section; fig. 8 a plan, and fig. 9 a cross section.

The general arrangement of the close furnaces, air-pumps, and pipes, common to my Fumific Impeller need not be described again here. The four or more wheels of the locomotive are placed upon the rails. E is a continuous tube or pipe similar to the pipes for atmospheric railway communication. Through the continuous opening at the part of the tube Æ, the pipe H is made to discharge the hot products of combustion, either through the valve U to impel the locomotive forward, or through the valve V to impel the locomotive backward, the discharge pipe from U delivering the hot products of combustion, the impact is got upon the air or aëriform fluid in the pipe Æ. The use of this pipe Æ being principally to prevent the lateral escape of the impelling and the resisting bodies, it may be made of iron or other suitable metal, or it may be constructed in masonry.

Instead of the continuous tube, as shown in figs. 7 and 8, a continuous trough of water or canal may be under or at the side of the railway, and the pipe H and delivering apparatus may be led so as to act under the surface of the water, whilst the weight to be carried, the close furnace and other machinery or apparatus are transported or borne on wheels or a carriage.

It is obvious that by causing an arrangement similar to the one above described (in figs. 6, 7, and 8,) to be employed in a carriage, to be impelled on a road surface other than a railway, or upon turf, or other way, the inertia may be overcome, and the carriage maintained in motion by the projection of the products of combustion backwards when the carriage is to be impelled forward, and forward when the carriage is to be backed. But in this case I prefer not to depend upon the products of combustion driven wholly into the surrounding atmosphere, but to force them diagonally downwards, so that impact may be had upon the road or way. In case of locomotion the air-pump is actuated by the revolution of the axle.

Fig. 9 is a sketch of an apparatus wherein the Fumific Impeller is applied to the raising of water from one level to another. J is a cylindrical working chamber which has been nearly filled with water from the level K through the pipe k, and communicates at top with the pipe at H. When the hot products of combustion enter J, their pressure on the surface of the contained water closes the inlet valve L of the pipe k, and forces the water up the pipe M to the higher level N.

We have seen, on pages 9 and 10, that part of the power obtained by the hot pro

ducts of combustion must be used for pumping air into the closed furnace. When water is pumped up, part of it must be used to work the pump; therefore, from N a portion of the water is returned back by the channel o to actuate a water-wheel O which works the blower D. The same water-wheel works the valves Q and S, which are necessary when the working chamber J is used. When the water in the working chamber has been depressed by the pressure to the level J', the water-wheel O opens the valve Q of a wastepipe R to permit the escape of the now expanded aëriform products, and closes simultaneously a valve h which commands the mouth of the pipe H. The working chamber J is now refilled with water from the level K by the superior pressure of the water in the direction of the pipe k and the valve L, and as soon as refilled, (or nearly so,) the water-wheel again opens the valve h, and the process of forcing up the water to N, above described, is repeated. On the top of the water in J there may be a float in one or more pieces of stone, wood, or hollow metal P, to prevent or lessen the splashing of water, and at the bottom of the chamber J there is a trap and man-hole door b, through which the ashes, cinders, and other solid matters which collect there may from time to time be withdrawn. When only one close furnace B and one working chamber J are employed, it is necessary that the blast of atmospheric air should be also regulated by the water-wheel O, or by manual or other power. But it is preferable to work with two close furnaces, two working chambers, and two blowers, (as shown in plan, fig. 10,) whereby a continuous action will be obtained. And in this latter case one waterwheel is sufficient for blowing the air and working the valves.

To start this engine it will suffice to use some water from the higher level N to set the water-wheel and blower in motion, but should there be no water in the higher level N, it will be necessary to inject a small quantity of water or solution of nitre into the close furnace, as explained in describing fig.

1.

A branch pipe from the rising main M may be laid so as to throw some of the first water raised by J upon the water-wheel.

Readers acquainted with the early history of the steam-engine will recognise in the working-chamber of this engine (figs. 9 and 10) an action of hot air similar to the action of steam in the proposition of the Marquis of Worcester, and in the practice of Savery and of Papin, as they are described by Tredgold and by Farey.