1366 THE COLLIERY GUARDIAN. December 27, 1918. produced, and the water tubes are not liable to obstruc- tions. (Four claims.) 120640. Drills for Boring in Rock, Etc. W. Lindley, Holly Dene, Coalville, Leicester.—This invention relates to improvements in percussive rock drills, and has for its object to effect economy in the use of such tools, and to increase their life, durability and efficiency. The inven- tion is not concerned with the drills of deep boring appli- ances, deep boring being an art quite distinct from what is generally understood by the term percussive rock drilling. The tool of a percussive rock drill comprises three principal parts, namely, a .rod or bar generally called the steel, a cutter head or bit on one end of the steel, and a shank or stem on the opposite end of the steel, the shank or stem being adapted for insertion in or engagement with the chuck or socket of the percussive drill. In certain types of such drill it has been pro- posed to make these three parts separately, and to screw the bit and shank to respective ends of the steel, which latter has in some cases been made tubular. In other types of such drill the hollow steel, in some cases with a de- tachable bit, has been supplied with water or air by means of a supply ring or sleeve surrounding ports formed in the steel, and such air or water has been conveyed to and delivered from passages and ports formed in the bit. The present invention consists, firstly, in making in three parts a percussive drill of the well-known collared type, the bit and shank being secured in respective ends of a length of tubing and the shank part comprising the usual collar and stem of angle section for engaging the chuck or socket of the drill; and, secondly, in providing, just in advance of the said collar, ports and means for attach- ing a liquid or air supply ring whereby liquid or fluid may be delivered to the point of the drill. The supply ring is mounted between collars screwing on the steel, or on to a gland or sleeve thereon, or between the integral collar of the shank and a collar screwing on to a portion of' the shank in advance of such integral collar. (Six claims.) 120645. Couplings or Sockets for Timber Pit Props. L. Worthington, The Villas, Bolsover, Chesterfield.—The invention has for its object to reclaim or re-use a large percentage of pit props that have been damaged in the mine and so fit them up that they can be again used for the purpose they were originally intended for by pre- paring the ends of the sound timber to fit within the socket pieces, the sockets being made of a length to make the combination socket and timber ends suitable for use where the shorter prop could not be employed for strutting or propping purposes. It has been proposed previously (a) to couple sections of wooden pit props by metallic couplers having double sockets with parallel sides and with or without an external collar or sleeve for strengthening purposes; (6) to remove the damaged parts from old wooden pit props so as to utilise the good parts or short lengths by uniting them through the agency of metallic coupling members or sockets to form a composite pit prop ; (c) to couple the sections of wooden pit props by means of metallic couplers having taper sockets in opposed rela- tion to receive spigot ends of the wooden sections, and, further, to provide such metallic couplers with strengthen- ing means in the form of longitudinal ribs on the exterior of said couplers, extending to or towards the open ends of the couplings, each of said ends being strengthened by a circumferential bead. The present invention has refer- ence to that type of coupling member wherein taper or conical chambers are in opposed relation to receive and maintain the spigot ends of the wooden members of a composite pit prop, and the said invention is mainly characterised by the couplings or sockets being formed of inner and outer members, the former members consti- tuting the sockets, and the latter members acting as binding means to resist stress or compressive strain. This construction of couplings or sockets also provides, or is combined with, means for the ready removal of damaged or renewal of wooden parts. (Ten claims.) 120650. Jib Cranes. T. G. Gardner, 87, Ladysmith- avenue, Seven Kings, Essex, and G. D. Hepburn, 13, Clifford-street, Ibrox, Glasgow.—This invention has rela- tion to improvements in cranes, and it refers more par- ticularly to jib cranes. The invention has for its object to provide a safety device by the use of which the move- ment of the load in both directions may be limited. According to the present invention, a safety device of the kind described above for cranes comprises the com- bination with a brake for the winding drum of means for applying the brake operated by the travel of the rope. along the winding drum, for example, a bar operatively connected to the brake and to the rope as by two pro- jections extending from the bar, one on each side of the rope. Preferably, the means for applying the brake com- prises the combination with a pivoted lever by which the brake is applied, of a bar operatively connected to the rope as by two projections extending from the bar, one on each side of the rope, and an operative connection between the bar and the lever. The bar may be provided with a slot or depression, and the operative connection between it and the lever may then comprise a depending extension, preferably weighted, of the lever adapted to drop into the depression for the purpose of operating the brake at a predetermined point, that is at the point where the rope has been wound on to, or unwound from, the winding drum to such an amount that in its travel across the drum it has moved the bar into the position with its depression under the depending extension of the brake lever. (Seven claims.) 120661. Appliance for Detecting Combustible Gases, Etc. A. Williams and L. D. Williams, 16, Hauteville-court, Stamford Brook, London, W. 6, and the Thames Trading- Company Limited, Canada House, Norfolk-street, Strand, London, W.C. 2.—This invention relates to an improved method and apparatus whereby a warning will be auto- matically given of the presence to an undesired degree of combustible gases or vapours in the atmosphere of a mine or a store where such gases or vapours are liable to be evolved. In carrying out the invention, use is made of the well-known effect of catalytic agents, such as finely divided platinum or palladium, in promoting the combina- tion of the combustible gases and the oxygen of the air. The heat resulting from this chemical combination and a heating source as hereafter mentioned melts or softens the element, and the weakening or destruction of the element is made to bring into operation an electrical, mechanical, or other energy relay for the purpose of giving an audible or visible signal which indicates the presence to an undesired extent of the gas or vapour in question. In order that the said catalytic substance may be main- tained in a condition ready to perform the function desired, it is, as is well known, necessary to maintain it at a temperature somewhat in excess of that of the surrounding atmosphere. To do this a simple electrical heater consisting of a resistance placed around or in proximity to the catalytic agent is employed. This source of heat may be sufficient in some cases when concentrated on a stream of the gas-impregnated atmosphere to induce such a degree of combustion of the gas or vapour as to generate enough heat for the desired purpose without relying on a catalytic action. It has already been propose! to use a catalyst to promote the chemical combination of the mine gases with the air, the resulting heat then acting on a fuse. For instance, a current of electricity has been passed through a platinum wire in series with a lamp. The platinum acts as a catalyst, and the heat of combina- tion of thef gases (added to the heat generated by the current) raises the temperature of the wire, thereby in- creasing its resistance, ultimately bringing about its fusion, and so giving the required warning owing to the lamp being extinguished. (Eight claims.) EXPLOSIVES IN COAL MINES. . The following is a complete list of Permitted Explo- sives to date:— Part 1.—Explosives which have Test. Explosive. Abbcite No. 2 Passed the Permissible maximum charge in oz. 18 Rotherham Pendulum swing in inches.* .... 2*54 Abelite No. 1 14 2*85 Abelite No. 4 18 279 Ajax Powder 12 2*69 Ammonite 18 2*44 Ammonite No. 1 4 24 2*42 Ammonite No. 4 30 1*76 Ammonite No. 5 i 26 2*41 Anchorite 14 .... 2*73 A. 1. Monobel 28 2*78 A. 2. Monobel 22 2*44 Arkite No. 2 40 2*41 Bellite No. 1 20 2'74 Bellite No. 2 32 2*42 Bellite No. 4... 18 2*92 Black Bellite 30 2*48 Britonite No. 2 ; 24 2*26 Britonite No. 3 24 2*17 Cambrite 30 1*98 <'ambrite No. 2 24 200 Denaby Powder 18 2*74 ' .. Dreadnought Powder 32 2*05 du Pont Permissible No. I .. .. 18 >*82 Dynobel 22 2*61 Dynobel No. 2 24 2*46 Dynobel No. 3 18 2*50 Dynobel No. 4 30 2*35 Essex Powder 38 2*17 Expedite 32 2*62 Faversham Powder No. 2 24 2*61 Hay lite No. 1 10 2*18 ■ Haylite No. 2 18 1*96 Haylite No. 3 16 2*44 Herculite 16 2*72 Kentite ... 18 2*64 Kent Powder 32 201 Kynarkite 20 2*21 Kynarkite No. 2 28 2*06 Melling Powder 12 2*62 Mersey Powder 18 2 60 Monarkite 26 2*67 Monobel No. 1 10 2*81 Nationalite No. 1 12 2*92 Nationalite No. 2 20 2*63 Negro Powder No. 2 20 2*21 Neonal 16 2*56 Neonal No. 1.... 30 2*51 New Fortex • 10 2*61 Nitro-Densite 28 1*47 Pit-ite No. 2 32 2*15 Pitsea Powder No. 2 8 2*64 Rex Powder 20 2*61 Eoburite No. 4 18 2*86 Seamex 36 2*54 Stomonal No. 1 20 2*68 Stomonal No. 2 30 2*57 Stomonal No. 3 22 2*56 Sunderite 16 2*66 Super-Cliffite No. 1 26 2*53 Super-Cliffite No. 2 3) 2*53 Super-Curtisite 16 2*71 Super-Excellite 10 2*74 Super-Excellite No. 2 14 2*72 Super-Excellite No.. 3, 36 2*73 Super-Kolax ? 30 2*i0 Super-Kolax No. 2... 32 2*21 Super-Rippite 18 2*53 Swale Powder : 20 ... ’2*50 Thames Powder 32 2*78 Thames Powder No. 2 22 2*59 Victor Powder 18 2 96 Victor Powder No. 2 16 2*63 Viking Powder No. 1 26 2 44 Viking Powder No. 2 18 2*59 Westfalite No. 3 12 2’55 Part 2. Bobbinite. (Permitted only for the purpose of bringing down coal in certain mines, and only until 31st December, 1920.) * This is the swing given to the ballistic pendulum at the Home Office Testing Station by firing at it a shot of 4oz. of the explosive. It may be compared with the swing of 3’27 in. given by a shot of 4 oz. of gelignite containing 60 per cent, of nitro-glycerine. Coal from Spitsbergen.—The Norwegian Spitsbergen Company ' at the general meeting last week resolved to increase the. coal output by 50 per cent., thus reaching a total of 60,000 tons next season. Government and Coal Carbonisation.—Mr. W. J. Fisher (chairman) stated at ’die meeting of the British Coalite Company Limited, last week, that the past year had been very largely one of experiment, and as the Barnsley plant was the first of its kind to be erected anywhere in the world it would no doubt serve a valuable instructional purpose. A large quantity was supplied to the Admiralty, and was very favourably reported upon. They were,-how- ever, not to be left in undisputed possession of the whole field of low-temperature carbonisation. There were other Richmonds in the field, or preparing to enter it. He was surprised to read that Sir Alfred Mond recently said the Government were constructing a large experimenting fac- tory to test the carbonisation of coal a: low temperatures, and was prepared to spend £150,000 upon the experiment. He was not blaming Sir Alfred Mond or the Government for any efforts :hey might make to increase the national reasources, even though private interests might suffer; but they were entitled to feel surpised ;hat this company, considering its successes, was not consulted. THE FREIGHT MARKET. Business in the north-east coast outward chartering market has since last report been wholly confined to fix- tures for scheduled destinations and Scandinavian ports, the latter, of course, being contingent upon the granting of special licences so far as the embargoed countries of Sweden and Denmark are concerned. At South Wales French Atlantic destinations have monopolised nearly all the transactions, the only fixture for elsewhere being that reported for Bilbao at 70s., Cardiff loading. A report which gained circulation that on the Cardiff market a steamer was offering for Genoa at 15s. per ton—an absurd rumour on the face of it—turned out to be based on the fact that that rate was being offered for tonnage by the Italian State Railways. It was quite unattractive, how- ever, owners’ ideas being in the region of four times that amount. A notice has been posted on the Cardiff Exchange, stating that the Inter-Allied Chartering Executive has decreed that all free neutral steamers must conform to the schedule rates of freight for British and Allied ships. For instance, Rouen must be,fixed for at not more than 18s. 6d., and St. Nazaire at not more than 23s. Up to the time of writing this insimation had not reached the north-east coast, but there can be no doubt that it will be of general application. It should considerably benefit French coal consumers at present drawing their supplies from this country by cheapening the delivered price of the commodity. ' Homewards, the general position at the River Plate is unaltered, steamers being ssill quoted at 62s. 6d., and sailers at 50s., from the lower ports to the United Kingdom. At the United States business is brisk. Northern Range io the United Kingdom on net form of charter is mentioned at 55s., with 60s. to North France and 65s. to the Bay. Gulf to United Kingdom is listed at 60s. The coal trade with Soush America is quiet, but there is an active request for general cargo space. Tonnage ,at all Far Eastern centres is scarce, and rates are well maintained. The time charter market is quiet, shere being practically no tonnage on offer. Tyne to Carentan, near ..Cherbourg, 280, 54s., sail; Christiania, 1,300-1,250, 25 kr.; Gothenburg, 800, 55 kr.; and Stockholm, 2,050, 75 kr. Cardiff to Bilbao 70s.; Cherbourg, 1,150, 37s. 3d., neutral; Granville, 160, 42s. 9d., sail and 700, 40s. 3d., neutral; Honfleur, 850, 28s., neutral, and 700, 21s. 6d., Allied; La Pallice, 1,900-1,950, 46s. 6d., neutral; L’Orient, 800-875, 46s. 6d., neutral; Rouen, 950, 23s.' 6d., Allied; 900, 40s. 3d., neutral; 1,400 and 1,500, 38s. 9d., neutral; Sz Malo, 250 and 350, 38s., neutral; 950, 17s., British; and St. Nazaire, 1,400, 46s. 6d., neutral. Middlesbrough to Rouen, 350, 52s., pitch. Newport to Rouen, 1,700, 38s. 9d., neutral; and L’Orient, 800, 46s. 6d., neutral. Swansea to Treport, 850, 38s. 9d., neutral; Rouen, 1,250 and 1,500-1,560, 38s. 9d., neutral; and Marans, 600, 52s. 6d., neutral. Fowey ;o New York, 2,500, 25s., china clay. Methil to Stockholm, 1,000, 75 kr. CONTRACTS OPEN FOR COAL AND COKE. A'nr Contracts Advertised in this issue received too late 4or inclusion in this column, sep Leader and Last A'hitk pages. Abstracts of Contracts Open. Hendon, January 6.—Coal and coke (12 months) for the Urban District Council. Forms from the engineer, Council offices, Hendon. London, January 6.—Coke, pitch, tar, creosote oil, and carbolic powder for St. Pancras Borough Council. Forms from the borough engineer, Town Hall, Pancras-road. The date given is the latest upon which tenders can be received. CONTRACTS OPEN FOR ENGINEERING, IRON AND STEEL WORK, Ac. Melbourne, January 8.—Spring Washers.—500,000 spring washers for fish bolts for Victorian Government rail- ways. Specifications may be seen at the Inquiry Office, Department of Overseas Trade, 73, , Basinghall-street, London, E.C. PUBLICATIONS RECEIVED. Bulletin and Comptes Rendus Mensuels de la Soc. de 1’Industrie Minerale (5me Serie, Tome 15, 3e Livraison de 1918; The M. and C. Apprentices’ Mag., Vol. 2, No. 8; Oxyacetylene Welding of Copper, Brasses and Bronzes, by M. R. Amedeo, Translated, with Additions, by D. Richardson; 80 pp.; 29 illus. (London : Raggett and Co.); 2s. 6d. net; Industrial Management—The Engineering Magazine, Vol. 56, No. 6, December 1918, price 35 cents; Journal of the Franklin Institute, Vol. 186, No. 6, December 1918, single numbers 50 cents; The Journal of the Chemical, Metallurgical and Mining •Society of South Africa, Vol. 19, No. 4, October 1918, single copies 3s. Anthracite Coal for the Army.—Arrangements have been made by the Coal Control Department to substitute an- thracite for bituminous in Army supplies. It is proposed to substitute in the ration 50 per cent, anthracite in lieu of bituminous coal, and, as supplies are forthcoming, to increase the percentage :o 75 per cent, of anthracite. This will apply to all hutted camps or Army living quarters where closed stoves are used, both at home and overseas. The coarser grades of anthracite will be used in the substitution Victorian State Mining.—The Victorian Railway Com- missioners issued some particulars relative to the State coal mine. It appears that after the payment of working expenses and interest charges there was a surplus of £5,159 for the past financial year, but the report adds that the approximate loss of tonnage of 72,283 tons as compared with the estimate was due principally to variations in the mining conditions and strikes of employees, which, with loss of time, on account of stop-work meetings, etc., diminished the number of working days for the year by 25|, and resulted in a reduction of approximately 25,000 in the number of shifts. As the result of these and other factors, working expenses per ton of coal produced amounted to 13s. Id., and are estimated to be equivalent to 14s. Id. for the current year. The higher cost of pro- duction led to higher prices being charged to railways and public.