January 31, 1913. THE COLLIERY GUARDIAN. 249 ABSTRACTS OF PATENT SPECIFICATIONS RECENTLY ACCEPTED. 77 (1912). Improvements in Rock Drills. H. Edgar, of Karangahake, Auckland, New Zealand. — This invention relates to rook drills of the type in which a double- headed piston is adapted to be reciprocated within a cylinder provided with a fixed partition, the motive fluid being conveyed to, and exhausted from, the chambers formed on both sides of the partition between the latter and the heads of the piston. The object is gene- rally to improve a drill of this kind, particularly with a view of facilitating the removal of the parts, and the ready renewal of the working surface of the cylinder, and also to provide improved means for cooling the drill. The invention 5 . I FIG-3- 'ff' consists in a rock drill of the above type in which the partition is secured within the cylinder by means of liners arranged on either side thereof and retained in position by means provided at the ends of the cylinder. The invention also consists in providing improved means for preventing the escape of the cooling water to the interior parts of the drill. Fig. 1 is a central sectional elevation of the drill • fig. 2 a cross-section on A—A, and fig. 3 a similar section on B—B, fig. 4 is an enlarged sectional elevation of a tappet valve, and fig. 5 a plan of the middle part of fig. 1 omitting the tappet valves. (Six claims.) 78 (1912). Improvements relating to Portable Unspillable Electric Battery Lamps for use in Mines, Ships, and like places. T. Sparkes, of Hillington, Oriental-road, Woking.— According to this invention an electric safety lamp is provided, of the type* comprising a casing of wood, metal or other suitable material, for holding the electric cell, in combination with a readily removable hinged cover carrying the glow lamp, lamp glass, reflector, switch and means for locking the cover and casing in the closed position. Con- nection is made between the glow lamp, the switch and the battery by means of spring contacts mounted on the battery terminals. The locking device is of a self-locking type, which can only be opened by means of a magnet or a suitable key. On the upper surface of the battery is provided a chamber, communicating with the interior of the battery, and containing a spindle valve, made from ebonite or the like, which valve normally prevents any of the electrolyte escaping, should the lamp be upset. When charging the battery, this valve is automatically opened by means of a plug connection, as hereinafter described, which effects the double purpose of connecting the battery to the charging mains and at the same time opening the valve. The valve assumes its normal closed position when the charging plug connection is removed. To allow for the escape of gas which might be evolved after charging is finished, a Subsidiary valve is provided of a known type on the valve spindle, which subsidiary valve automatically opens when the pressure inside the cell reaches a predetermined point. The switch is of the barrel plunger type, and is provided with a gland which keeps the switch contact compartment gas-tight. A glow-lamp is used which has two or more filaments connected in parallel, so that in the event of one filament breaking, the person using the lamp would not be in darkness. Fig. 1 is a front elevation of a lamp, showing the cover and switch in section; fig. 2 is a side elevation, showing the cover and valve chamber in section ; fig. 3 is a plan view of the battery and casing, showing terminals and spring contacts in position; figs. 4 and 5 are side elevation and plan respectively of battery case and cover in part section, showing construction of self-locking device; and figs. 6 and 7 are plan and front elevation respectively of a charging plug connection. (Four claims.)) 9993 (1912). Improvements in Coke Loading and Screening Machines. E. Fabry, The White Building, Fitzalan-square, Sheffield.—The object of the invention is a coke loading and screening machine, which is characterised by the following features :—A : It is specially designed for use in conjunction with an inclined coke bench on which the coke discharged from any one coke oven is temporarily retained during its quenching and subsequent cooling. B: The design allows the coke to slide naturally from the coke bench on to the lower run of the coke conveyor without having to pass through any hopper, register or similar device liable to cause obstruction. C: The lower run of the endless push-plate conveyor is the only one brought into use for the screening and loading of the coke, this feature resulting in a shorter and lower machine, lighter weight and smaller first cost, as well as maintenance and repair. D : The screening of the coke is effected in a simple manner by providing fixed screening bars in part of the race of the coke pushplate conveyor and thereby removing the necessity of separate coke screens whether of the fixed or shaking fic.3 kind. The accompanying drawing illustrates the general arrangement of an electrically-driven coke-loading machine built in accordance with the present invention, fig. 1 being an elevation of the machine, and fig. 2 a plan. (One claim.) 10046 (1912). Improvements in or relating to Belt Con- veyors. B. A. Afzelius, of Sandviken, Sweden.—According to this invention two or more belts are used located side by side, which belts overlap each other somewhat at their edges. The said belts form together in cross-section a horizontal, flat or substantially flat surface; which supports the material to be conveyed in a manner as reliable as a single belt, and without the material being able to pass of the material being treated, and to enable material of varying sizes to be treated without adjusting the distances between the rotating magnet ring and the fixed magnets. In addition to the magnetisable ring forming the common armature for the fixed magnets, a second but non- magnetisable rotatable ring protects or shields the magnets and the field gaps of the magnetic fields from the material under treatment. The rings can be connected one with the other, or may be rotatable independently of each other about a common axis. In the latter case they may be given different speeds of rotation. A constructional form of the apparatus for carrying the invention into effect is illustrated in the accompanying drawing. (Two claims.) 29224 (1911). Improvements in or relating to Magnetic Separators. Fried Krupp Aktiengesellschaft Grusonwerk, of Magdeburg-Buckau, Germany.—This invention relates to magnetic separators having a number of magnetic fields. through the same. In this manner the conveyor belt may be made of the desired width, so that the belts, mounted edgewise or in a slanting position, which are generally used and form the side walls of the trough, can be dispensed with. One end of the conveying device in question is shown in a side view in fig. 1, in cross-section in fig. 2, and in a plan view in fig. 3. (Two claims.) 28974 (1911). New or Improved Explosives and Method of Manufacturing the same. Dr. F. Baschig, Chemical Works, Ludwigshafen-am-Ehine, Germany, chemist.—This invention relates to explosives of the kind which contain a combustible part and a carrier of oxygen such as any of the technically suitable nitrates, that is to say preferably potassium nitrate, sodium nitrate, ammonium nitrate, and calcium nitrate, or else chlorates or perchlorates. According to the invention the combustible ingredients consist of substances particularly suitable for the purpose in view— namely, the sulphonated salts of the higher phenols, which are contained in the tar oils (the distillates of the coal tars) which are capable of being easily and cheaply produced in large quantities. Among these substances special mention must be made of the ammonium, sodium, potassium calcium, or magnesium monosulphonates of cresol, xylenol, cuminol, naphthol. Disulphonates of the named higher phenols are, however, also suitable; and equally applicable are mixtures of all these substances. The following examples may serve to explain the method of preparing the improved explosives. In each instance the quantity used for the test was 10 grammes, and the test employed was the well-known Trauzl test. Example 1: 69 parts of sodium nitrate and 31 parts of sodium cresol-sulphonate are treated with 10 parts of water and are kneaded together energeti- cally for two hours. The product is dried for 24 hours at 80 degs. and then forms an explosive giving an expansion of 57 cubic centimetres in the Trauzl test. Example 2 . 86 parts of ammonium nitrate and 14 parts of sodium cresolsulphonate are kneaded energetically with 10 parts of water for two hours. The product is then dried for 24 hours at 80 degs. and then forms an explosive, 10 grammes of which when exploded by a detonator in the Trauzl block produces an expansion of 320 cubic centimetres. A modification of the method of preparing the explosives consists in dissolving the combustible substances—all of which are soluble in water—in a solution of the oxygen carrier with which they are to be incorporated, for example a solution containing the corresponding quantity of a nitrate or chlorate and then evaporating the entire liquid to dryness. The liquid must be stirred continuously while being evaporated; but a still better method and one perfectly free from danger is to allow the liquid to run in a thin stream over rotating rollers preferably heated internally to above 100 degs. by steam. Example 3: 69 parts of sodium nitrate and 31 parts of sodium cresolsulphonate are dissolved together in water and evaporated to dryness, with stirring. The residual powder is a powerful explosive of the blasting-powder type; 10 grammes when exploded in the Trauzl lead block by means of a fuse produce an expansion of 59 cubic centimetres. (Black powder under the same conditions gives an expansion of 55 cubic centi- metres.) Example 4: 70 parts of sodium nitrate and 30 parts of sodium xylenolsulphonate furnish an explosive producing an expansion of 62 cubic centimetres. Example 5: 86 parts of ammonium nitrate and 14 parts of sodium cresolsulphonate furnish an explosive producing an expansion of 355 cubic centimetres. (Three claims.) 29201 (1911). Improvements in or relating to Magnetic Separators. Fried Krupp Aktiengesellschaft Grusonwerk of Magdeburg-Buckau, Germany.—This invention relates to magnetic separators of the kind in which magnets are arranged in a circle around a vertical axis, and over which a magnetisable ring rotatable about the said axis revolves and acts as a common armature for the said magnets. The chief object is to prevent the accumulation in the field gap ax The invention consists in the combination, with a magnetic separator having a fixed magnet pole and a fixed armature or two fixed magnetic poles in the magnetic field of each working place, of a non-magnetisable rotating carrying member, which protects or shields the magnet poles or the (Continued on page 252.)