To obviate the difficulty arising from such properties, and procure the instantaneous release of the armature, a piece of ivory or other non-conducting substance is interposed between the armature and one or both poles of the magnet, so as to prevent actual magnetic continuity.

Fig. 4, represents, in front view, a modification of the above described apparatus (the steam, as a motive power, being, in this instance, dispensed with); and fig. 5, is a vertical section of the same. Instead of the central passage in the pillar A, for the issue of the steam to the whistle, being carried up in a continuous vertical line, it is bent out in a horizontal direction, and returned again to its vertical line, for the purpose of forming a seat for a valve E; the action of which is to cut off the passage of the steam, or let it on to the whistle, as required. Connected to the valve E, is a vertical rod a, which slides in a steam-tight box, and is jointed to one end of a horizontal rocking lever b, supported by the stud of bracket-arms c, which are bolted to the pillar A. The other end of the rocking lever b, carries the armature m, which is acted on, as before described, by the electro-magnet F. d, is a coiled spring, for returning the valve to its seat. The whistle is placed, as before, at the top of the pillar a. When an audible signal is required to be given by this apparatus, the circuit is completed; and the current of electricity will then run through the coils of wire surrounding the bar of iron F, and convert it into an electro-magnet. Its attractive force will then draw down the armature m, and thereby lift the valve from its seat. The steam from the locomotive e gine boiler will then rise up the pillar and pass to the whistle, which will continue to sound an alarm until the circuit is broken. e, is a cock, under the command of the engineer, for cutting off the steam from the whistle when required, irrespective of the other parts of the apparatus.

en

The mode of forming the metallic connection, for the electric current to pass to the signal apparatus, at the desire of any person in the train, will now be described. Fig. 6, represents, in sectional elevation, two railway carriages, furnished with electric conducting wires, the wires of one carriage being connected to those of the other, to allow of the

electric current passing from one to the other. The end of
a locomotive boiler is also shewn, as carrying the signal ap-
paratus, which is brought into the electric circuit by the
conducting wires, as shewn. Fig. 7, is a plan view of the
carriage framing, shewing the position of the conducting
wires. A, is the galvanic trough or battery, which may be
fixed beneath the body of any one of the carriages of a train,
or beneath the engine or tender; and to the negative and
positive ends of the battery the conducting wires a, a, are
attached, as usual. These wires are, at their other ends,
secured to isolated metal staples b, b, in the end framing.
c, is another wire, running parallel with the line of wires a,
and connected at each end with isolated staples d, d. Every
carriage in the train is provided with two lines of wires,
which are secured in their places by isolated staples. There
are also vertical wires e, e, joined to the horizontal wires, and
connected, at their upper ends, with an apparatus B, which,
when required, brings the two wires into metallic contact,
and thus (when the signal apparatus is brought into con-
nection with the battery by the wires f, f) completes the
electric circuit. The means which are employed for obtain-
ing a metallic connection, of variable length, between the con-
ducting wires of the several carriages of the train, is a spring
clip and jointed staple, pendent from their respective car-
riages, as shewn in the drawings; but any other convenient
means may be adopted. The apparatus B, which completes
and breaks the circuit, as required, is placed, for convenience,
in the side of the carriage, at the command of the passengers;
it is shewn detached, and on an enlarged scale, at figs. 8, 9,
and 10. By the peculiar construction of this apparatus, which
is denominated the detective communicator, the guard may
readily ascertain from what carriage the alarm, whether ne-
cessary or fictitious, has proceeded. Fig. 8, represents the
apparatus as it would appear within the carriage; fig. 9, is a
cross section, in the line 1, 2, of fig. 8; and fig. 10, is a view
in the line 3, 4, of fig. 9. a, is a knob of ivory or other non-
conducting substance, attached to a sliding pin b, which car-
ries a non-conducting ring or collar c, for a bolt d, to rest

against. This bolt has always an inclination to move forwards; it being pressed against by a spring e, attached to the disc f. g, is a spring, also attached to the disc ƒ, and intended to press against the pin b, and keep the knob a, in the position shewn in the drawing. To these springs e, and g, the vertical conducting wires are respectively connected. When therefore the knob a, is forced inwards to a recess made for its reception, the end of the bolt d, comes into contact with the metal pin b, and completes the electric circuit, whereby the signal apparatus on the engine is put into action. In order that the guard may ascertain, by inspection, from which carriage the alarm has been sounded, the pin b, is con-tinued through the side of the carriage; and to its outer end a knob h, is attached, which will protrude when the circuit has been completed, and remain in that position until released. This is effected by the guard inserting a key and forcing back the bolt d, when the spring g, returns the parts to their former position.

In order to convey intelligence to the engineer by signals pre-arranged between him and the guards (such signals consisting of two or more rapidly succeeding sounds of the whistle) the patentee proposes that there shall be no locking in the apparatus B, for the guards' carriages, but that the surface of the non-conducting collar c, shall be flush with the surface of the pin b, so that the pin may be quickly returned to its original position by the spring g, and thus a rapid succession of sounds, by repeatedly completing and breaking the circuit, may be effccted.

The last part of the invention, which refers to the communicating of intelligence between distant places on a line of railway, consists in the employment of the improved arrangements of apparatus, before described, in connection with the stationary telegraph wires of railways; but as the whistle of such apparatus requires a rush of steam or other vapour to bring it into action, it is obvious that the application is limited to those parts of a line where stationary engines are employed, such as at the mouth of tunnels, the commencement of heavy gradients, &c.: in the case of atmospheric railways, however, it may be used at almost every station. The mode

of actuating the apparatus, when thus applied, being precisely similar to that described with reference to the train of carriages, no further explanation will be necessary.

The patentee claims, First, the combined application of electro-magnetism and steam, or other elastic fluid, for turning the stop-cocks of railway whistles, whereby signals or intelligence by means of signals, may be conveyed from one part of a railway-train to another; and also the general arrangement of apparatus, as shewn at figs. 1, 2, and 3, for effecting this operation. Secondly, the mode of working the signal-whistle of a railway-train, through the agency of electro-magnetism, as described with reference to figs. 4, and 5. Thirdly,-the mode of bringing the electric circuit within the command of the passengers or guards of a train, as described; and particularly the construction and employment of the detective communicator, whereby a visible proof of which carriage the signal proceeded from will be presented to the guard. And, Lastly, he claims the application, to railways generally, of the improved arrangements of electromagnetic apparatus above described; such apparatus being brought into connection with the stationary telegraph wires and the steam or vapour generators of stationary engines, as above explained.—[Inrolled in the Petty Bag Office, August, 1848.]

To STEPHEN WHITE, of No. 2, Caroline-street, Morningtoncrescent, gas patentee, for a new means of producing gas, both as to apparatus and materials from which the gas is produced. [Sealed 15th April, 1847.]

THIS invention applies to the production of gas for illumination, and consists, so far as it relates to the materials from which such gas is produced, in decomposing water by bringing it into contact, in the manner hereinafter described, with charcoal, coke, or anthracite coal, and small thin plates of iron, or small pieces of thin iron wire, or with charcoal, or coke, or anthracite coal and lime, at a very high temperature, and thereby producing, from such combination of materials so treated, hydrogen gas and oxide of carbon gas mixed; and

afterwards in combining such compound gas with carburetted hydrogen gas, produced by bringing tar, oil, or fat, or certain other substances, hereinafter designated or described, in contact with heated materials, so as to produce, ultimately, a compound gas, composed of hydrogen gas, oxide of carbon gas, and carburetted hydrogen gas, mixed together; which compound gas is fitted for the purpose of illumination. The invention also relates to the use of certain apparatus for manufacturing the illuminating gas.

In Plate VIII., fig. 1, is a front view of the whole apparatus; fig. 2, a section, taken through the centre of the three retorts hereinafter particularly described; and fig. 3, is a transverse section of the brickwork in which the retorts are set, shewing an end view of the apparatus. a, b, c, represent three cylinders or retorts, all made of cast-iron, placed perpendicularly, and supported by the brickwork d, d, and by bars of iron e, e, e, placed longitudinally, and supporting the flanges or shoulders at the lower ends of the cylinders or retorts. The cylinders or retorts a, and b, which are intended for the decomposition of water, are nearly filled to the top, as shewn in fig. 2, with charcoal, or coke, or anthracite. coal, and iron plates or wires ;-the charcoal, or coke, or anthracite coal, being broken in small pieces and placed in the retorts, and the iron plates or wires being contained in the cylindrical colanders f, f. g, is a vessel, from which water is supplied in a small continued stream, regulated by the cock h, through the tube i, into the cylinder or retort a, see fig. 2. The water is conveyed through the said pipe into the iron panj, and diffuses itself over and penetrates to some depth into the mass of heated charcoal, or coke, or anthracite coal, and iron plates or wires, by means of which it is converted into vapour; and such vapour having no outlet at the upper end of the cylinder or retort (which is closed, as hereinafter described) penetrates and passes through the whole body of charcoal, or coke, or anthracite coal, and iron plates, contained in the cylinders and colanders, down to the bottom of the said cylinders, when it is allowed to escape through the connecting tube k, k, into the next cylinder or retort b, and to rise therein through the charcoal, or coke, or anthracite