440 THE COLLIERY GUARDIAN. August 27, 1915. from said pawl, a wheel adapted to receive such a step-by- step movement and having a rim studded with characters adapted to register with an aperture in a screen, said characters denoting the order of impulse, and means for restoring the reciprocatory member to initial position. The invention is illustrated in the accompanying drawings, in which fig. 1 is a side elevation partly in section, fig. 2 is a plan, and figs. 3 and 4 detail views. The arrangement is such that as the requisite number of impulses are transmitted through the system, the pawl engages the teeth of the reciprocatory member and moves the latter step by step (each step or stage corresponding to an impulse) towards a rocking member 16 secured to a drum 16a loose on the shaft of the crank member, and adapted to oscillate around the axis of said crank member, said member 16 being in a state of unstable equilibrium and operatively connected at 17 to a valve (not shown) serving to control admission of steam to the cylinder of the winding engine. The arrangement is such that, in the execution of the final step (e.g., the third step) of the series, the said rocking member is engaged by a pin 18 formed on the reciprocatory member 7, and the equilibrium of the former is disturbed, whereby the said rocking member 16 acts under the influence of gravity to control the valve aforesaid. The reciprocatory member 7 is adapted to be restored to normal position by a striker 19 deriving the requisite motion from the crosshead or other moving part of the winding engine, as indicated conven- tionally at 22, through the intermediary of levers 20 and 21. To permit such restoration of the member 7 the pawl 2a may be disengaged from the teeth 8 by manual displace- ment of the member indicated at 3a. (Two claims.) 8939 (1914). Improvements in or connected with Appliances for Supplying Oxygen or Air to Divers and others. W. J. Mellersh-Jackson, of the firm of Haseltine, Lake and Company, 28, Southampton-buildings, London. (Commu- nication from the firm of Dragerwerk, Heinr. und Bernh. Drager, Moislingerallee No. 53, Lubeck, Germany.)— Relates to portable breathing apparatus, and refers more particularly to the kind of apparatus having a pressure- reducing valve, and means whereby a direct flow’ of fluid may be set up should the reducing valve become inoperative. The reducing valve provided according to this invention is of the -Ecf- 1. FiCf.2. J Im class in which the valve proper is connected to and operated in unison with a flexible diaphragm, manually operable means being provided to control the valve in the event of the same ceasing to act automatically. In apparatus constructed according to the invention, the reducing valve is provided with means for controlling the valve proper by hand in the event of the same ceasing to act automatically, comprising a cam which can be operated from the exterior by a suitable manipulating handle, and w’hich acts upon the valve directly or a movable support for the spring of the diaphragm, which tends to lift the valve from its seat, which support when moved from outside in a certain direction increases the ten- sion of the spring so as to raise the valve from its seat, over- coming any resistance. When the reducing valve is used in connection with mixing devices for the gas, a relief valve is preferably used which prevents the pressure in front of the mixing device from increasing to too great an extent, when the reducing valve, as explained above, is moved by hand, in which case means may be employed for conducting the gas escaping by way of the relief valve into the breathing passages of the apparatus. With this object in view, the outlet of the relief valve opens into a chamber, which in other respects is closed, but is connected by channels with the breathing passages or breathing bags, thus when opening the reducing valve by hand the compressed gas will not escape into the atmosphere, but is conducted to the breathing organs. Big. 1 is a longitudinal section of such part of the apparatus as is necessary to show the invention applied; fig. 2 is a section on the line 2—2 of fig. 1. (Three claims.) 10157 (1914). Improvements in or relating to Water Purifying Apparatus. The firm Maschinenbau-Anstalt Humboldt, of Cologne-Kalk, Germany.—The object is to <30 ee- provide an improved water purifying apparatus which works quite automatically, this result being obtained by the co-operation of syphons and floats with valves operated by the same. The improved apparatus consists substantially of an upper tank or other reservoir and a preheater, both of which are provided with syphons, in such a manner, that one syphon draws the water from the tank into the pre- heater, whereas the second syphon draws the preheated and purified water into the filter, both the preheater as well as the tank being provided with floats so as to control auto- matically the admission of steam in accordance with the inquired time of boiling, as well as the escape of the water trom the preheater. By way of supplement, a tank or basin is provided for the purifying agent from which tank or basin the said agent is automatically drawn by suction at the proper moment by means of a small auxiliary syphon. Fig. 1 is a sectional view of a detail of the improved apparatus on the line A—B of fig. 2, whereas fig. 2 is a sectional view showing the whole improved water purifying apparatus. (Four claims.) 13062 (1914). Electric Signalling Systems particularly for use in Mines. Sterling Telephone and Electric Company Limited and F. G. Bell, of 210-212, Tottenham Court-road, London. (A communication from the Telephon Fabrik Akt.- Ges. vorm. J. Berliner, of 18, Kniestrasse, Hanover, Ger- many.)—According to the invention, a contact maker or key is provided, in which the operating lever normally rests in, and returns, under its own weight, to a position from which it can be brought to the operating position only by move- ment substantially opposite in direction to the actual oper- ating movement. In the normal position of rest the key may make a second contact. Successive contacts for signalling cause partial closing of the circuits of successive visual signals, while the contact made on release causes the com- pletion of the circuit of a visual signal. When there are a number of signalling positions, for example, that of the banksman and several onsetters, the visual signal produced from one position may be terminated by a further actuation of the key at that position. It may be arranged that the visual signals are controlled by relays which, upon succes- sive operations of the key, are connected in turn into a circuit which is completed upon release of the key. The actuation of each of these relays may complete a hold-up circuit for itself and also prepare the next relay to receive the next operating impulse, while also causing an interruption in the preceding visual signal. Or, again, the circuits of the signals may be partially closed by a selector, while, then, the release of the key not only completes the circuits of a visual signal, but also causes the restoration of the selector. Fig. 1 is a cross section of the signalling key; and fig. 2 is a partial diagram of connections for a complete signalling system. For diagrams, see specification 18661, below. (Nine claims.) 18661 (1914). Electric Signalling Systems particularly for use in Mines. The Sterling Telephone and Electric Company Limited, F. G. Bell, and J. W. Dungey, all of 210-212, Tottenham Court-road, London, W.—Relates to an improvement in or modification of the systems of mine signalling described in patent application No. 13062 of 1914. Its main purposes are to effect economy in the number of relays necessary for a given system by enabling all neces- sary signalling operations to be carried out by a single relay for each visual signal; and to effect economy of current by retaining in circuit only the relay of the particular visual signal given. As in the system described with reference to fig. 2 of the former patent application, there are certain relays common to the whole system. The functions of these are slightly modified so that the first lamp relay is excited through a back contact, and one of them, a preparing relay, Kz Ki Kii I whose own exciting circuit the first lamp relay completes on excitation. The preparing relay completes a hold-up circuit for itself, and joins a front contact of the common relay, through which all the signalling impulses are transmitted to a system of lines and contacts connecting the remaining relays. There are two sets of lines, one extending from a front contact of one relay to the winding of the next, and so on throughout the whole system, the other extending from a back contact of one relay to an armature of the next co-oper- ating with a corresponding back contact, and so on through- out the series. Also each lamp relay when excited interrupts the hold-up circuit of the preceding relay. The effect, there- fore, of successive signal impulses is to excite one lamp relay, disconnect the preceding one, and connect the impulse circuit to the succeeding one. An arrangement according to the invention is shown in the accompanying drawing. (Six claims.) 16034 (1914). Improvements in or connected with Rock Drilling Machines. W. C. Stephens, of The Climax Rock Drill and Engineering Works Limited, Carn Brea, Cornwall. —Relates to rock drilling machines of the hammer type, and to that class of such drill wherein the shank of the borer projects through a chuck at the forward end of the cylinder so that it shall be directly struck by the piston. The object is to simplify the construction of the drill shank and also, when water circulation is provided for, to provide means for preventing the escape of the water from the chamber around the shank. In carrying out the invention, the steel of which the drill shank is constructed is flattened at the end only so as to give it the form of a chisel or pinch bar with a blunt edge, or instead of making it in this manner it can be formed with one flat or with three or more flats, as desired, the essential condition, however, being the formation of only the extreme end of the drill shank with one, two, three or more inclined sides which will fit into a correspondingly shaped socket or stop in the front cover or chuck of the drill and project into the drill cylinder so that it will be struck by the hammer, the said front cover being fixed so as to rotate with the drill and thereby corre- spondingly rotate or drive the drill shank of tool without employing a separate rotating device attached to the tool itself. In order to compensate for the wear due to the continual vibration to which the borer is subjected so that it will be caused to project to a uniform extent through the e Hf! v1 t1 V e O®E1 ti J , Ay? WjXEP cover, and also to provide for positioning the said borer in case one side of the stop or socket wears more than the other, there are arranged in the cover one or more movable jaws or blocks, according to the number of flats formed upon the borer, the said jaws or blocks being adjustable in a radial direction with relation to the axis of the borer, the faces of the blocks with which the borer comes in contact being inclined to correspond with the inclination of the said flats. In order to introduce water into the borer there is combined with the front cover before referred to a sleeve through which the borer has to be passed to introduce the end into the front cover, the said sleeve having an opening formed in it at one side to enable it to be attached to the water supply, and to prevent the water from escaping around the borer there are provided within the sleeve packing rings of concavo-convex form in cross section. Fig. 1 is a side view partly in section of a front portion of a drill having the improvements applied to it; fig. 2 is a plan view of the chuck end of the drill; fig. 3 is a section on line 3—3, fig. 1; fig. 4 is a section on the line 4—4, fig. 1; figs. 5 and 6 are a side view and end view respectively of one of the jaws or blocks of the chuck; figs. 7 and 8 are views at right angles to each other illustrating the arrange- ments for preventing the water from escaping around the borer when a solid chuck is used. (Five claims.) 16035 (1914). Improvements in Valve Gear for Rock Drilling and like Machines. W.C. Stephens, of The Climax Rock Drill and Engineering Works Limited, Carn Brea, Cornwall.—Relates to valve gear especially applicable for use in connection with rock drilling machines of the hammer type (but also applicable to similar engines or machines for other purposes), the object being to simplify the construction of the valve and the ports for the admission and escape of the driving fluid, whereby the efficiency of the machine is improved. In the machine constructed according to the invention, the distributing valve, which is of the hollow type, provided with collars and grooves, which co-operate with ports in the valve chest, is adapted at its rear end to slide upon a spill or stud, which serves for differentiating the area of Y.-.Vmz . Kg7 v F