August 6, 1915. _THE COLLIERY GUARDIAN.__303 —... —z_r ’ Koppers’ Coke Oven Is undoubtedly the most successful Bye-Product Oven on the market. Since its introduction a little over 10 years ago there have been built 12,500 KOPPERS’ OYENS. KOPPERS’ OVENS ARE AT WORK HEATED BY PRODUCER GAS AND BLAST FURNACE GAS. KOPPERS’ DIRECT RECOVERY PROCESS IS THE SIMPLEST ANO MOST EFFICIENT SYSTEM OF AMMONIA RECOVERY. PLANTS ERECTED FOR THE RECOVERY OF BENZOL & TOLUOL, FOR TAR DISTILLATION & THE MANUFACTURE OF SULPHURIC ACID. Full particulars on application to - The Keppers’ Coke Oven and Bye-Product Co. 301, GLOSSOP ROAD, SHEFFIELD. r J.B. TREASURE HUGE VflUXHfllLR? LLIVERPOOL^ GAUGE GLASS WASHERS LUBRICflTORSnc ’HMIIIIIIIIIIIlfBir I/STS (M PPPI/&77M. LASSES Price 3s. 6d. Post Free. STEEL & FILES. FANSHAWE & MARRIOTT ATKINSON, Steel and File Manufacturers, Ecclesfield, near Sheffield. Telegraphic Address: »♦ Fansha, Ecclesfield.” CORRUGATED and FLAT SHEETS and GALVANISED GOODS; TUB & CORNER PLATES; AIR PIPES and all Colliery Requirements. J. SUMMERHILL & CO., Beaver Works, WOLVERHAMPTON. ELECTRIC CIRCUIT PROBLEMS A Practical Handbook for Colliery Electricians. IK MINES AND FACTORIES. By ELLIS H. (TR APPER, B.Eng., M.I.E.E., Head o/ the Department of Electrical Engineering at the University of Sheffield. THE COLLIERY GUARDIAN CO. LTD., 30 & 31, Furnival Street, Holborn, London, E.C. HAGGIE BROS. Ltd. Telephone—No. 7 Aberdare. Telegraphic Address—“ Lamps, Aberdare.” Gateshead- on - Tyne. Established 1800. MANUFACTURERS OF IMPROVED PATENT Flat and Round Wire and Hemp ROPES OF ANY LENGTH FOR COLLIERIES AND RAILWAYS, FROM EITHER BEST SELECTED CHARCOAL IRON, IMPROVED PATENT OR PLOUGH STEEL WIRE. . . Flexible Galvanized Steel Hawsers (all guaranteed to Lloyd’s test), with Winches or Reels and Stoppers. Wire Signal Lines for Railways and Collieries. Copper Lightning Conductors, complete. Galvanized Fencing Strand. Galvanized Wire Rope for Ships’ Rigging. Galvanized Wire Rope fitted up to order. Picture and Sash Cord made from Copper, Brass Plated or Galvanized Wire. Crane Ropes, made to suit small Drums and Pulleys. We have Crane Hopes working on the same Barrels as Chains. Wire Rope Springs; Wire Rope Pulleys. Wire Rope Composition or Grease. White Block Ropes and general Hemp Cordage. Chains of every description. Wire Ropes made specially to suit small Pulleys. We can guarantee uniformity of all our Ropes, as we draw our own Wire from Special Rods, got up to our own specification. Owing to our “Special Quality/9 have Haulage Ropes running 14 years and Winding Ropes years. Telegrams—” Hag