Practical guides to economy IF YOU USE Liquid fuel you will welcome suggestions that will make it possible to get more work out of every gallon consumed. Whether you use petroleum fuel, gas or diesel oils, creosote or creosote/ pitch mixture, you have at your disposal expert advice on how to reduce losses and wastage and improve the operational efficiency of your plant. The advice is given in these three Bulletins : THE INDUSTRIAL USE OF HEAVY-OIL ENGINES LIQUID FUEL (Bulletin No. 24) A valuable reference to the correct fluidity of various fuel oils at the point of usage; to the care of burners and the effective control of combustion; the recovery of waste heat from furnace flue gases; better furnace loading.