September 20, 1918. THE COLLIERY GUARDIAN. 589 By Tests The Best “SINGLE HOOD” RESULT OF LATEST TRIAL o/ COAL 0 1Q°/ INCREASE /o SAVED & | J /o evaporation “PERFECTA” BOILER CIRCULATOR Ltd., 39, Victoria Street, LONDON, S.W. 1. AIR COMPRESSORS Standard Types up to 5,000 c. ft. per min. Fitted with special light weight valves, forced lubrication and thorough intercooling arrangements. Special Types for Air and Gas storage at high pressures up to 6,000 lb. per square inch. MAKERS also of High-Speed STEAM ENGINES, STEAM TURBINES, High and Low Lift Centrifugal Pumps, AND FANS for all purposes. ■ ■ ■ PETER BROTHERHOOD LTD., MANCHESTER ; Mansfield Chambers, D ET E D D A D A11 P U GLASGOW: R. HENDERSON, St. Ann’s Square. lElEllDUIlUUulla 48, West Regent Street.