September 1, 1916. THE COLLIERY GUARDIAN. 433 Keppers’ 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’ OVENS. KOPPERS’ OVENS ARE AT WORK HEATED BY PRODUCER GAS AND BLAST FURNACE GAS. Koppers’ Direct Recovery Process IS THE SIMPLEST AND 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 3oi, glossop road, Sheffield. -iztzzrz- STEAM, MOTOR, BELT, OR ROPE-DRIVEN AIR & GAS COMPRESSORS From 50 to 15,000 cubic feet FOR COLLIERIES, MINES, Etc. ■ff' 1 STEAM-DRIVEN AIR COMPRESSOR. ADVANTAGES SIMPLICITY. RELIABILITY. DURABILITY. HIGH EFFICIENCY. SELF-LUBRICATION. BEST WORKMANSHIP. SMALL FLOOR SPACE. MINIMUM MAINTENANCE MOTOR-DRIVEN AIR COMPRESSOR. BELLISS Telegrams : BELLISS, BIRMINGHAM.” & MORCOM LIMITED, BIRMINGHAM. London Office : 8, VICTORIA STREET, S.W.