area of condensing surface. Advantages and disadvantages of surface condensers and reasons for employing them.

Form and volume of jet-condensers. Sea-cock and injection-pipe. Injectionvalve. Bilge-injection.

Air-pump; description; volume for maintaining a proper vacuum in a given condenser. Description of lifting air-pump. India-rubber valves. The Indret jet-condenser for a screw-engine. Double-acting air-pump. Hot-well; reliefvalve; outboard-delivery valve. Discharge-pipe.

Complete description of a surface-condenser for an engine of the Indret type. Method of action of the surface-condenser. Circulation of the steam and of the cold water. Methods of fixing the tube in the tube-sheet. Distilling-apparatus for fresh water.

7. Transmission of movement. -Mazeline's cross-head. Cross-heads of the Indret type.

Connecting-rod, type Indret, with club ends. Mazeline's connecting-rod, stub end. Cross-head guides, cross-head, and connecting-rod for an inverted cylinder engine.

Mazeline's crank-shaft bearings. Bearings of the "Forges et Chantiers" type. Crank-shaft; angle between the cranks. Valve-gear counter-shaft.

Siphon lubricator. Lubricator with valve. Crank-pin and wrist-pin lubricators. 8.-Apparatus for feeding and for pumping out bilge.-Feed-pumps. Donkey engine; its valve chamber.

Giffard's injector; its principle. Description of the Giffard feeding apparatus. Behrens's rotary engine.

Bilge-pumps. Jet-bilge pump.

Friedmann's ejector. Centrifugal pump.

III.

Propellers.

1.-Paddle-wheels.-Geometrical description; mode of action. Causes of loss of power; slip. Elements of paddle-wheels. Position and number of wheels. Advance and slip. Rolling circle. Different systems of paddle-wheels; wheels with feathering paddles.

2.-The screw.-Definitions. Mode of action. Causes of loss of power; slip. Elements. Position and number of screws. Advance and slip. Fixed and variable pitch. Classification and description of various screws; type Mangin. Screw with spherical hub and bent-back blades. New model of screw. Line of shafting. Cardan's coupling and hand-turning gear. Movable coupling and break. Stern-pipe and screw-shaft. Thrust-bearing. Stern stuffing-box. Outboard bearing of screw-shaft.

IV.

Regulation, work, and employment of marine engines.

1.- Curves representing the motions of the slide-valve. --Representation of the simultaneous movement of the piston and slide-valve; curves of piston-speeds. Motion curve of a 3-ported slide. Variation of the angle of lead. Relative positions of piston and slide-valve. Motion curve of a D slide-valve. Determination of the action of a slide-valve by means of the motion of any given point in the valve.

Determination of the elements necessary for a graphic representation of the motion of a slide-valve. Determination of the dead centers of the piston and slide. Determination of the lap. Operations necessary for determining the relative position of the piston and slide-valve.

Drawing of a sketch of the arrangement and position of the ports. Analysis of the operations of the slide-valve. Drawing of a D-valve. Adjustment of the

valve-stem and angle of eccentric by means of a motion-diagram. Case of a link. Observations relative to the valve-diagram for a backing motion.

2.-Work of the steam in the engine.-Theory of the indicator. Primitive indicator of Watt. Drawing of a diagram from the analysis of the working of the slidevalve. Measurement of the pressure by means of the indicator-diagram. The surface of the diagram represents the effective work of the steam upon a square centimeter of the surface of the piston.

Garnier's indicator, new model. Richards's indicator.

Fitting the indicator on an engine. Adjustment of the indicator. Disarrangement of the indicator. Representation of an indicator-curve. Tracing of the atmospheric line.

Calculation of the mean effort on the pistons. Mean vacuum in the cylinder; correction by means of the barometric pressure. Calculation of the power of an engine by the mean effort found by the indicator-curves. Nominal, indicated, and actual horse-power. Work on the shaft. Old formula for nominal horsepower.

Calculation of the consumption of steam by the indicator-curve; common method. Labrousse's method.

3.-Regulation and working of compound engines.-Definitions and classification. Continuous-expansion engine. Method of producing expansion. Effective admission and expansion. Actual expansion; indicator curves.

Compound engine with cranks at 90°. Method of producing expansion. Curves of volumes, and indicator-curves.

Three-cylinder compound engine, with cranks at 90° and 135°. Expansion apparatus. Curves of volumes and indicator-curves. Adjustment of the slide-valves according to the angle of the cranks.

Advantages and disadvantages of Woolf engines. Calculation of the effective horse-power of Woolf engines by means of indicator curves. Actual mean effort; fictitious mean effort. Calculation of the consumption of steam.

4.-Efficiency of engines.—Analysis of indicator-curves under various conditions. Reduction of pressure between the boiler and the cylinder, and between the cylinder and the condenser. Contracted passages and their employment with wet steam. Undulations of curves. Leakage past the slide-valve. Leakage past the piston. Insufficient steam-lead. Working with low pressure and late cutoff. Working at low pressure with early cut-off. Three-ported slide-valve, with valve-stem too short. Angular advance of eccentric too great and valvestem two long. Length of indicator-cord badly adjusted. Determination of average horse-power and speed at trials of engines. Relation between the speed of the ship, the indicated power of the pistons, and the slip of the propelling instrument. Coefficient of speed. Consumption of coal per indicated horse-power per hour. Consumption of coal per square meter of gratesurface per hour. Efficiency of combustible. Loss of heat in engines.

V.

Manipulation peculiar to each of the principal types of engines in actual use, including boat engines.

1.—Maneuvers.-Preparations for starting. Heating the engine; blowing through and turning over. Starting; stopping; backing. Regulating the speed; increasing and moderating speed.

2.-Care of the engine while in use..-Cylinders, slide-valves, and distribution of steam. Condensation. Movement of the machinery. Feed-pumps and bilge-pumps. 3.-Accidents to the engine.-Heating of bearings. Dangerous pounding. Leaks. Heating of the condenser. Filling up of the condenser. Air-leaks. Leaks in the condenser-tube packing.

4.-Management of boat engines.

VI.

Injuries of engines and boilers.

1.-Boiler explosions.-Two kinds, by rupture and by bursting; causes and means of prevention. Escape of water by the safety-valve. Explosive combinations in the flues.

2.-Spontaneous combustion of coal. Causes. Indications of the heating of coal; precautions to be taken. Fire in the coal-bunkers.

3.-Injuries to the cylinder; measures to be taken for working the engine with the parts left intact; engine with simple cut-off, Multiple-cylinder continuous-expansion engine. Woolf engine, with cranks at 90°. Three-cylinder engine, with cranks at 90° and 135°.

NOTE M.

BILL OF FARE.

Menu des repas des élèves pour la journée du 18 juin 1878 et pour le lendemain matin.

DÎNER.

Potage au vermicelli.

Boeuf aux choux.
Petits pois au beurre.

Fraises.

SOUPER.

Mouton rôti.

Pommes de terre (maître d'hôtel).
Compote de prunes.

DÉJEUNER.

Café au lait.

Beurre.

NOTE N.

PROGRAMME OF EXAMINATIONS.

SCHOOL OF MACHINISTS, FRENCH NAVY.

CANDIDATES FOR FIRST MASTERS.

CHAPTER I.

Arithmetic, algebra, geometry, plane trigonometry.

Square and square root of whole numbers.

Square and square root of fractions.

Cube of whole numbers and fractions.

System of weights and measures.

Relation between the metric system and the English system of weights and measures.. Ratio and proportion.

Arithmetical and geometrical progression.

Theory of logarithms. Use of tables.

Elementary processes of algebra.

Solution of equations of the first degree with one or more unknown quantities.

Solution of equations of the second degree with one unknown quantity.

Properties of right lines and of angles.

Equality of triangles.

Properties of parallel lines, rectangles, and polygons; of the circle; properties of

chords, secants, and tangents.

Measurement of angles. Relative position of two circumferences.

Proportional lines. Similar polygons.

Problems of plane geometry.

Regular polygons. Measurement of plane surfaces; of the circumference and of the area of a circle.

Parallel and perpendicular planes and right lines. Dihedral angles.

Properties of prisms and pyramids. Superficial area and volume. Volume of the frustum of a prism, parallelopiped, and pyramid. Superficial area and volume of a cylinder, of a cone, of the frustum of a cone, and of a sphere.

Solid contents of a coal-bunker.

Definitions of the principal trigonometric lines.

Solution of right triangles.

CHAPTER II.

Mechanics and physics.

Elementary notions of matter; inertia, motion, velocity.

Forces; weight and density of bodies. Measurement of force. Mass and its determination.

Composition of concurrent forces. Decomposition of a force into two others acting in any given direction. Composition of parallel forces.

Centers of gravity. Practical determination of the center of gravity of any body whatever. Determination of the centers of gravity of geometrical surfaces and the principal solids.

Work of forces; its graphical representation and measure. The kilogrammeter and the horse-power.

Principle of the transmission of work in the case of a uniform motion: Application to the equilibrium of simple mechanics. Passive resistances. Necessity of regulating the motion of machines. Fly-wheels. The efficiency of a machine. Action and equilibrium of the lever; of pulleys. The differential pulley. Action of the connecting-rod, of the crank, of the eccentric, and of cams. Action, equilibrium, and drawing of parallel and conical toothed wheels. Action and equilibrium of the screw; of the endless screw. Watt's parallelogram. Equilibrium of the inclined plane and of the wedge, taking into account the effect of friction; of the winch, and of the windlass or capstan. The differential windlass. Strength of materials.

Equality of pressure of fluids. Calculation of the pressure exerted upon a given surface.

Air, atmospheric pressure. Different methods of determining pressure in engines. Vacuum, and methods of determining it. Construction and use of the barometer. Effects produced upon bodies by the increase or diminution of heat. Construction and use of the thermometer. Expansion and contraction of metals. Precautions to be taken in consequence of the expansion and contraction of metals in the construction, erection, repair, and management of engines. Shrinkage, tempering, annealing. Expansion of fluids. Particular effects of the action of heat on water.

Measurement of heat.

Calorific capacity or specific heat of bodies, latent heat. Propagation of heat. Effects of surfaces of various colors and of polished surfaces. Good and bad conductors. Heating of liquids by circulation. Means of preventing loss of heat, and the overheating of furnace doors and chimneys. Principle of transformation of heat into work, and vice versa. Mechanical equivalent of heat. Carnot's theorem.

Fundamental principles of boilers, combustion, furnaces.

Gases: expansion, tension. Mariotte's and Gay-Lussac's laws.

Theory of the siphon.

Theory and description of the suction-pump; of the force-pump, and the double-acting pump; of centrifugal and rotary pumps.

Hydraulic press.

Evaporation, vaporization, boiling, conversion into steam.

General properties of steam. Saturated steam, heated and superheated steam. Spheroidal condition of water. Bourdon's manometer. Compressed-air manometers. Condensation of steam. Problems relating to jet and surface condensers. Principle of the condenser. Action of single and double acting air pumps. Hot-well. Measurement of condensation; vacuum gauge. Different forms of condenser-barometers.

CHAPTER III.

Theory and description of engines.

Fixed and variable cut-offs; their use, advantages, and inconveniences.
Theory and action of compound engines.

'Theory of slide-valves; lap; angles of lap and lead; relations between the movement of the slide-valve and that of piston; steam and exhaust lead; fixed cut-off; compression. Theory of variable cut-offs. Reversement of motion; different methods of producing it.

Classification of marine engines, according to the method of using the steam, the mode of transmission of movement of piston to shaft, and according to the kind of propeller. Advantages and disadvantages of the different kinds of engines. Necessity of a number of cylinders; equalization of movement.

Description and working of an oscillating engine; of a back-acting engine, ordinary and compound; of a trunk-engine. Brotherhood's engine. Principal types of hoisting machines.

Properties and use of metals and other substances employed in the construction of engines.

Description of slide-valves; locomotive and double-ported slide-valves; box-valves;
D and piston valves, long and short. Fitting slide-valves in oscillating engines.
Principal starting-gear; Stephenson's link; system of Creusot; systems of Mazeline
and of Dupuy de Lôme; systems of oscillating engines.
Description of the principal systems of variable cut-off.

Principal systems of throttle-valves of marine engines.

Action and description of the different kinds of surface-condenser and of distilling apparatus.

Bed-frame, foundation-plates, framing and flooring of engines. Lubricators. The screw and its elements. Advance and slip. Different types of screws. Various arrangements for carrying the screw and screw-shaft. Fitting the screw upon the shaft. Description of a line of shafting. Stern stuffing-box and thrust-bearing. Paddle-wheels and their parts; different systems. Advance and slip. Classification of marine boilers in relation to their pressure, their interior arrangement, and their shape. Complete description of a rectangular tubular boiler. Description of a cylindical tubular boiler of the authorized pattern. Detailed description of a Belleville generator. Complete system of pipes of a system of boilers. Plates used in the construction of boilers; their assemblage. Furnaces, ash-pits, fire