144 THE COLLIERY GUARDIAN. January 15, 1915. liquor (that is, the water of condensation from the gases) pass from the condensers into a separator of any suitable known construction, and are automatically separated by decantation, the tar passing to the tar well. The virgin liquor overflows from the separator into a heat exchanger, preferably in the form of a tank fitted with a coil of piping, through which cold Water is passed. The virgin liquor gives up its heat to the water, and the water thus heated may be used as the supply for a usual water jacket surrounding the producer, thus facilitating the production of steam in that jacket. The now cooled virgin liquor is led to a tower, to which the cooled gases are also led, the liquor and gases passing through this tower in opposite directions, so that the ammonia is thoroughly washed from the gas by this liquor, and as the latter jis thoroughly cooled before it enters the washing tower, a strong ammonia liquor solution is obtained. Where the gas is further cooled after leaving the tar extractor, and before it reaches the washing tower, the water of condensation from these condensers is led back to the chest or chests of the first set of condensers, so that all the virgin liquor is collected at one place. A typical apparatus for the carrying out of the improved process is diagram- matically illustrated in the accompanying drawings, fig. 1 being an elevation and fig. 2 a plan. (Three claims.) 7647 (1914). Improvements in Safety Explosives. A. C. Pearcy, of 110, Cannon-street, London, and Curtis’s and Harvey Limited, of 110, Cannon-street, aforesaid. — The object is to produce an improved explosive of the gelatinous class which, among other merits, will have that of offering advantages in respect of safety in use in gaseous or dusty coal mines. The following may be given as typical examples of the composition of the new explosives :— I. II. Parts. Parts. Nitroglycerine................... 42| ... 52*0 Collodion cotton.................. 2| ... 3 0 Nitrate of potassium ............ 20 ... 15'0 Borax ........................... 20 ... 22’0 Chloride of sodium .............. 15 ... 8*0 100 ... 100’0 The weight of borax in each case represents ordinary com- mercial hydrated borax before removal of any water of crystallisation. The foregoing compounds both yield highly satisfactory explosives of the kind specified, but it has been found that the jelly (that is to say, the nitro glycerine and collodion cotton together) may be varied from 45 to 65 per cent., the nitrate of potassium may be varied from 10 to 25 per cent., the borax from 15 to 30 per cent., and chloride of potassium or the chloride of sodium from 5 to 15 per cent, of the finished explosive, and that within these limits the specific effects already described are practically secured. The jelly components may be varied so as to contain slightly higher or lower proportions of collodion cotton in relation to the nitro glycerine. (Three claims.) 10841 (1914). Improvements in and Relating to Mining Bells. W. A. Heyes and L. O. Heyes, both of Water-Heyes Electrical Works, Riverside, Wigan, Lancashire.—Relates to improvements in mining bells, more particularly the type described in previous patent No. 3692 of 1904, in which a diaphragm or other flexible member conveys the hammer blows through the casing containing the actuating mechanism of the bell to the bell itself. The object is to provide means, whereby if gas in any way leaks into the enclosed casing and an explosion takes place, then an additional protection is added, whereby the excessive motion of the diaphragm is prevented, but in case the diaphragm is broken or injured, the passage of the heated gases to the external atmosphere will be prevented except through a joint of sufficient length to cool the gases beyond the danger point. According to the invention, the intermediate member, which is attached to the diaphragm, and conveys the blow from the hammer to the bell, is surrounded by a suitable collar acting as a pro- tecting member, which in case of an explosion taking place within the casing, forces the intermediate member into position against the collar, so as to prevent excessive motion of the diaphragm, and in case of damage thereto the leakage of the gas to the outside air. In a preferred form this member, which is attached to the diaphragm, is shaped like a cone or part of a cone, the collar which surrounds it being of only slightly wider diameter, and having a similar bevelled edge into which the cone is adapted to fit. The accompany- ing drawing represents an elevation of the bell, showing in section the improvement according to the invention. (Five claims.) 10901 (1914). A Mechanical Signalling Apparatus for Use in Mines and other places. B. Trawford, of 74, High- street, Bloxwich, Staffordshire. — Relates to signalling apparatus of the kind used in mines and other placesin which by successive pulls on a rope or by other mechanical means, successive movements of an indicator or indicators are brought about so as to display a numerical signal or like indication. The signals, of which there may be any number, are indicated by numerals, and the nature of each signal is stated above each numeral. Fig. 1 is a front elevation of the apparatus, showing positions of signals when at zero; fig. 2 shows section 6 6; fig. 3 gives back elevation, showing automatic release gear. The apparatus is operated by means of the lever A, the travel of which, and return by spring O, between two stops, being required to indicate each signal, which will become visible in a transparent space in front plate d, which prevents any other signal than the one required from being seen. Each pull of lever A causing the bell a to ring once. When the signal No. 1 is required, the lever A carries the shaft D a portion of a revolution by means of the pawl B (which is raised out of gear on its return) and ratchet wheel C. The pawl T (kept in gear with a spring at bottom) engages a projection in the sleeve Q, which carries the stork P attached to a plate furnished with the signal No. 1, and renders the signal No. 1 visible by carrying it to the transparent space in front plate d. The lever A, in addition to revolving shaft D, simultaneously raises the piston and rod F in an air cylinder E (which is open to atmosphere at top and also at bottom through an adjustable valve K) by means of a toothed quadrant G secured to lever A, and toothed rack H (which slides verti- cally on the side of cylinder E) provided with a projection to engage the piston rod F. The quadrant G and rack H returns with lever A after each pull. When the piston and rod F are raised, the pawl L engages the ratchet wheel C, and prevents its return, and also the shaft D due to the spring M. When the lever A has returned after giving the signal, the piston and rod F falls by gravity, and the air on underside piston (which has been supplied by non-return valve J) is exhausting through an adjustable valve K, which regulates the falling speed of piston and rod F. When piston reaches bottom, of cylinder (provided with a vertical groove in side to allow air to exhaust freely when piston F nears bottom of cylinder, and so obtain the full benefit of the force of gravity on piston and rod F) piston rod F strikes the lever N, and pawl L is disengaged through a connecting rod between L and N, and allows shaft D and ratchet wheel C to return to zero, by means of spring M. Shaft D is prevented exceeding this position by stop k. The signal No. 1 still remains visible, being held by pawl V (which is mounted on a stationary shaft f, and kept engaged by a spring) and a ratchet on sleeve Q. Should the winding engine be now set in motion, the cam shaft Z, which is &n. I -R geared with the engine, revolves and trips out pawl V, and the weight W, which is attached to sleeve Q, returns the signal No. 1 to zero by gravity, and is prevented exceeding that position by stop t, which comes into contact with shaft f. If the signal No. 1 is required before the engine starts the operation as previously stated is repeated (as the piston and rod F have automatically returned the shaft D to zero) except that the pawl T travels in the groove in sleeve Q to the projection in same, but does not effect it, i.e., providing the winding engine is not set in motion, or any other signal given, the signal No. 1 remains visible indefinitely. When any other signal is required otherwise than No. 1, say No. 3 for example (which must be always followed by signal No. 1, as signal No. 1 is the commencement of a signal) the method is as follows :—The first pull of lever A gives signal No. 1 as previously explained. This brings the projection U in shaft D into line with sleeve S, which is slotted to allow No. 1 signal to be given before becoming effected. At the second pull of the lever the projection U forces the sleeve S, to which is attached the disc R, furnished with the signals Nos. 2, 3, 4, 5, a portion of a revolution, and the signal No. 2 becomes visible in the transparent space in front plate d. Simultaneously with the pulling of signal No. 2, the projection on rack H (working in a slot in piston rod F, which allows rack H to fall without effecting piston rod F) has come into contact with the top of slot in piston rod F, before the piston F has reached bottom of cylinder (having been raised by the first pull of lever A) and raised it to top of stroke, so preventing the shaft D from being released. Also the pawl T has been forced under the projection in sleeve Q, and past it, and the cam on sleeve S has disengaged the pawl V, which allows the signal No. 1 to return to zero by means of the weight W. The signal No. 2 remains visible, being held by pawl X (which is carried by stationary shaft f and kept engaged by a spring) and ratchets on sleeve S, of which there is one for each signal. When the third pull is given, the projection U carries the disc R a further portion of a revolution, and the signal No. 3 becomes visible, and is held in that position until another signal is given or could be released by cam shaft Z, owing to winding engine being started. Simultaneously with the pulling of No. 3, the projection on rack H has prevented the piston and rod F from releasing the shaft D, and has raised piston and rod F to top of stroke as explained. The signal required being now visible, the piston and rod F is free to fall gradually to bottom, and automatically the shaft D, as explained, is released and forced back to zero by spring M, and the pawl T is forced under projection in sleeve Q (now at zero posi- tion), and is pushed up into gear on the other side of projection by a spring on bottom. The next signal to be given will be No. 1 as stated previously, and the No. 1 and shaft D being at zero, the lever A when pulled will place signal No. 1 at the transparent space in front plate d. Previously the signal No. 3 was visible, and simultaneously with the pulling of No. 1, the stork P carrying signal No. 1, strikes pawl X, and releases the disc R, which returns to zero by means of spring Y, and is prevented exceeding that position by stop j. As a portion of disc R is cut away so that the disc R does not obstruct the view in transparent space in front plate d when R is at zero position, signal No. 1 is visible. This signal No. 1 can be displaced by giving another signal, or by winding engine when in motion. (Seven claims.) 13218 (1914). Improvements in Charging and Discharging Apparatus for Gas Retorts and the like. F. J. Bancroft and J. B. Hansford, both of the Barnet District Gas and Water Company, Station-road, New Barnet, Herts. — Relates primarily to charging and discharging apparatus for gas retorts, but may also be applied to other kinds of furnaces, such as refuse destructors of the type having a charging door at one side and a clinkering door at the other side, the object of the invention being to provide a charging and dis- charging apparatus whereby the retort or furnace can be filled substantially completely in one, two, or more shots or operations, and the coke or other residue after the distilla- tion or other furnace operation is completed can be pushed out at the farther or discharge end of the retort or furnace. Fig. 1 is a side view of one arrangement of the apparatus commencing to insert a charge into a retort; fig. 2 is a plan of same; fig. 3 is a side view, showing the apparatus fully withdrawn from the retort and the parts in position to discharge the retort; fig. 4 is a plan of same; fig. 5 is a section on line x—x of fig. 1; fig. 6 is a section on line y—y of fig. 3. The apparatus as shown is designed to be mounted in or on a suitable carriage or trolley, in which it is preferably made adjustable vertically. Mounted on the carriage or trolley, and made so as to be adjustable with the charging and discharging apparatus is a trough or the like A, of a shape approximately the same as that of the mouth of the retort or furnace B to be charged. This trough is also preferably made adjustable longitudinally, so that it may be moved right up against the mouth of the retort or furnace when it is to be charged. Over the trough is arranged a shoot 0 connected with a fuel bin or hopper carried by the carriage or trolley. An automaticallly operated door of known type may be provided at the bottom of the shoot to cut off the coal at the right times. Adapted to be moved longitudinally in the bottom of the trough and the retort or furnace is a plate or plates D, of a shape more or less the same as that of the bottom of the retort, so as to fit more or less closely thereto. This plate or plates during the charg- ing operation is pushed along the floor of the trough in any suitable manner, coal from the shoot C falling on it up to approximately the level of the top of the trough A, till the end of the plate or plates D comes under the shoot, when the shoot door is shut, and the head E is moved forward behind the charge into the retort. When the plate or plates D with the charge has been inserted the desired distance into the retort, the plate or plates D is withdrawn, and the head E remaining stationary, while the plate or plates D is with- drawn under it, the fuel is pushed off the plate or plates D on to the floor of the retort, practically filling it up to the top. The plates H carry brackets h, upon which are pivoted catches I. The rails G are also provided with recesses K, so that, when it is desired to push forward the plate D and head E in the position shown in figs. 3 and 4, it is only necessary to turn the catches J to the position shown in these figures, When they will so move forward together. In this position the head E may be employed for discharging a retort, the head being pushed into the retort or furnace mouth behind the coke or other residue which is discharged at the other end. The catches J may, as shown in dotted lines, also be employed for drawing back the head E and rails G. (Six claim's.) KEW PATENTS COMECTED WITH THE COAL AISD IRON TRADES. Applications for Patents. 93. Signalling apparatus for mines, lifts, and other like purposes. F. Lane and S. E. Williams. 103. Dynamo-electric machines for transforming alter- nating current into continuous current, or vice versa. J. L. La Cour. 117. Ambulance wagons and the like. Sunbeam Motor Car Company Limited, and L. Coatalen. 165. Reversible turbine. W. J. Bilham and P. H. Bilham. 177. Valve arrangements of reciprocating engines. W. Schmidt. 178. Power generating plants. British Thomson-Houston Company Limited, and F. Samuelson. 184. Mechanical stokers. J. S. S. Fulton and R. J. Morris. 220. Vaporising hydrocarbons. J. H. Robertson. 225. Distilling liquid hydrocarbon fuels for internal com- bustion engines. G. E. Heyl and T. T. Baker. 298. Railway and like couplings, j. Berryman. 337. Support for wires and the like. W. D. Reid, and Callender’s Cable and Construction Company Limited. 340. Process for desulphurising or deodorising mineral oils. G. E. Heyl and T. T. Baker. 347. Process and apparatus for the treatment of liquids or liquefied hydrocarbon bodies of the petroleum series or the like for the obtainment of light oils or the like and by-products therefrom. E. A. Ashcroft. (Continued on page 146.)