ocean steam, which is the cardinal point of interest in marine propulsion. SECTION IV. COST OF STEAM: OCEAN MAIL SPEED. MISAPPREHENSION OF THE HIGH COST OF STEAM MARINE PROPULSION: VIEWS OF THE NON-PROFESSIONAL: HIGH SPEED NECESSARY FOR THE DISTANCES IN OUR COUNTRY: WHAT IS THE COST OF HIGH ADEQUATE MAIL SPEED: FAST STEAMERS REQUIRE STRONGER PARTS IN EVERY THING: GREATER OUTLAY IN PRIME COST: MORE FREQUENT AND COSTLY REPAIRS: MORE WATCHFULNESS AND MEN: MORE COSTLY FUEL, ENGINEERS, FIREMEN, AND COAL-PASSERS: GREAT STRENGTH OF HULL REQUIRED: ALSO IN ENGINES, BOILERS, AND PARTS: WHY THE PRIME COST INCREASES: THEORY OF REPAIRS: FRICTION AND BREAKAGES: BOILERS AND FURNACES BURNING OUT: REPAIRS TWELVE TO EIGHTEEN PER CENT: DEPRECIATION: SEVERAL LINES CITED; USES FOR MORE MEN: EXTRA FUEL, AND LESS FREIGHT-ROOM: BRITISH TRADE AND COAL CONSUMPTION: THE NATURAL LAWS OF RESISTANCE, POWER, AND SPEED, WITH TABLE: THE RESISTANCE VARIES AS IS THE SQUARE OF THE VELOCITY: THE POWER, OR FUEL, VARIES AS THE CUBE OF THE VELOCITY: THE RATIONALE: AUTHORITIES CITED IN PROOF OF THE LAW: EXAMPLES, AND THE FORMULAE: COAL-TABLE; NO. I.: QUANTITY OF FUEL FOR DIFFERENT SPEEDS AND DISPLACEMENTS: DEDUCTIONS FROM THE TABLE: RATES AT WHICH INCREASED SPEED INCREASES THE CONSUMPTION OF FUEL: CONSUMPTION FOR VESSELS OF 2,500, 3,000, AND 6,000 TONS DISPLACEMENT: COAL-TABLE; NO. II.: FREIGHT-TABLE; NO. III.: AS SPEED AND POWER INCREASE FREIGHT AND PASSENGER ROOM DECREASE: FREIGHT AND FARE REDUCED: SPEED OF VARIOUS LINES: FREIGHT-COST: COAL AND CARGO; NO. IV.: MR. ATHERTON'S VIEWS OF FREIGHT TRANSPORT.