-DESCRIPTIVE GEOMETRY.

Find the projections of the intersection of two given planes.

6.-FRENCH.

DICTATION.-Auguste aima mieux alors recevoir les lois dures de son vainqueur que de ses sujets. Il se détermina à demander la paix au roi de Suède, et voulut entamer avec lui un traité secret. Il fallait cacher cette démarche au sénat qu'il regardait comme un ennemi encore plus intraitable.-(Voltaire.) Continue the reading with explanations.

7.-GEOGRAPHY.

1.-Draw a map of the Spanish peninsula. Give an account of its physical geography, and fix the position of the principal cities.

2.-Give the political history of the county of Venaissin, and describe its physical characteristics.

8.-HISTORY.

1.-Give an account of the Ostrogoths and their origin. Narrate the events of the reign of Theodoric, noting the system of government, the legislation, and the extent of Theodoric's kingdom.

2.-Give a full account of the foundation of the Kingdom of the two Sicilies.

The Norman conquest of Sicily.

9.-ENGLISH.

1.-ENGLISH TRANSLATION.-On exposait une peinture

Où l'artisan avait tracé

Un lion d'immense stature

Par un seul homme terrassé.

Les regardants en tiraient gloire.

Un lion en passant rabattit leur caquet:

"Je vois bien, dit-il, qu'en effet,

On vous donne ici la victoire,

Mais l'ouvrier vous a déçus;

Il avait liberté de feindre;

Avec plus de raison nous aurions le dessus,

Si mes confrères savaient peindre."

2.-Dictation at the blackboard of a passage from Columbus.

3.-Construction and force of the words no, one, however, indulge, unknown, how, show, blow, height.

10.-LATIN.

Translate Cæsar, B. G., I. 47, from Biduo post Ariovistus to aliquem ad se mitteret, giving explanations of allusions. Give the construction and force of perfectæ, agi, iterum; mode and tense of constitueret, vellet; force of cœpta. Decline aliquem, is, hic, suum.

11.-GREEK.

Translate Xenophon, Anabasis, I, 4, § 11, from "Evrεvlev έže avver to óvóμaтi.
Conjugate and give construction of ἐξελαύνει. Decline εύρος, μεγάλη.

S. Ex. 51-21

NOTE K.

COURSE IN ENGLISH NAUTICAL LANGUAGE ON BOARD THE BORDA.

[Extracts.]

A ship is said to be sailing before the wind when she has the wind right aft. Both sheets are then hauled aft, the sails are set at right angles with the keel; the staysails are hauled down, and the mainsail is drawn up in the brails, that the wind may act upon the foresail; the helm is put amidships, and the only thing the steersman has to do is to put the helm a little to starboard or larboard, in order to keep the vessel from yawing.

COMMANDS IN TACKING.

Ready about, or Ready all-Pare à virer.

Haul over the boom-Bordez le gui.

Helm alee gently—Labarre dessous en douceur.

About ship-Envoyez.

Ease off; or, Let go the jib sheets-Filez les focs.

Up tacks and sheets-Lère les lofs.

(Stand by, or Get to the) after braces-Aux bras de derrière. Haul mainsail, haul—Derrière changez.

Sheet the jibs; or

Haul aft the jib-sheets. } Bordez les focs.

Clear or coil the ropes-Parez les manœuvres.

A compound engine is one that uses the same steam at both high and low pressure, the object being to take as much elastic force as possible out of the steam before condensing it.

Gun-cotton is easily exploded by percussion or ignition, and any weight of this preparation is a good deal more effective than the equivalent weight of gunpowder. It is well-suited to the working and blowing up of mines, but is not used for military purposes, on account of the facility with which it may be ignited by friction, percussion, and heat.

NOTE L.

SYLLABUS OF LECTURES ON MARINE ENGINEERING.-BORDA.

FIRST YEAR.

I.

Elementary study of the action of a marine engine.

Latent heat of
Bourdon's ma-

1.-Steam.-Definitions; saturated steam, dry and wet steam, superheated steam; formation, superheating, and condensation of steam. Pressure. steam. Instruments for measuring the pressure and vacuum. nometer. Vacuum indicator. Density of dry saturated steam.

2.-Elementary explanation of the action and working of steam in a cylinder.-Essential parts of an engine. Introduction, exhaustion; absolute pressure; back pressure; effective pressure. Condensing and non-condensing engines. Condenser, vacuum. Back pressure in the cylinder compared with the pressure in the boiler. Double-acting engine; single-acting engine; atmospheric engine. Mechanical work. Kilogrammeter; horse-power. Work of a force acting in the direction of the motion, or otherwise. Graphic representation of the work of a variable or constant force. Mean effort of a variable effort. Moving force, resisting force, and effective force of steam in a cylinder. Advantages of the condenser. Effective power of engines in the different conditions of working. 3.-Transmission of movement from the piston to the shaft.-Connecting rod and crank. Dead centers; travel of the piston from one dead center to the other; top and bottom of a cylinder; names of the dead centers and of the strokes of the piston. Simultaneous positions of the crank, piston, and connecting-rod; half-stroke. Angularity of the connecting-rod; its influence. Summary notions of the correlative movements of the piston and the shaft. 4.-Elementary explanation of the regulation of engines.-Expansion: change of motion of the piston. Limited admission; leads; compression; clearance. Graphic representation of the effective work of the steam in the cylinder, taking into account the adjustment of the valve-gear. Advantage of the exhaust-lead. Curves of expansion. Graphic construction of the general equation PVa = P。V。= constant. Particular case where x = 1; that is, the case most often met with. Theoretical expression of the work of steam during expansion. Advantages and inconveniences of expansion. Action of the steam-jacket.

II.

Complete description of a screw-engine. Classification of the principal systems.

1.-General description of an elementary screw-engine.

2.-Mode of action of detail parts.-Transmission of movement. Distribution of steam. Jet and surface condensers. Advantages of surface condensers. Boiler-feeding apparatus. Bilge-pump.

3.-Classification of marine engines, principal systems.-Classification. Geometrical description. Beam engine. Oscillating engine. Direct-acting engine. Backacting engine. Trunk engine.

III.

Complete exposition of the distribution of the steam by the slide-valve or by separate cut-off

gear.

1.-The eccentric.-Its working. Description of the transmission of movement by a fixed eccentric; by eccentric with variable angular advance. Example of system of hooking-on gear.

2.-Slide-valves.-Definitions. Valve-faces; valve-seats. Two kinds of slide-valve. Elementary description of the working of a three-ported slide-valve. D-valve; explanation of its working. Comparison of the working of the two kinds of slide-valves.

Adjustment of a slide-valve; stroke; attachment of the valve-stema. Angle of lead. Lap. Total area of ports. Results of the adjustment of a slide-valve. Steam-lead. Greatest opening of the ports. Wire-drawing steam. Exhaustlead. Compression. Résumé of the functions of the slide-valve. 3.-Mechanism of the reversing-gear.-Principle of the reversement of motion. Means of carrying out this principle. Geometrical study of the reversing mechanism. First system: Single eccentric, with variable advance: (1) by means of a slipeccentric; (2) by means of an adjustable eccentric. Mazeline's system.

Second system: Two eccentrics, with fixed advance: (1) drop-hook motion; system of Creusot; (2) by link-work. Stephenson's link.

4. Variable cut-offs.-Variable cut-offs driven by cams; by an adjustable eccentric, the cut-off valve being wide open at the end of a stroke; at half-stroke. Cutoff driven by a fixed eccentric, the stroke of the expansion-valve being variable, and the valve opening wide at the end of a stroke; at half-stroke.

1.-Division and classification.

IV.
Steam-generators.

2.-Ordinary rectangular boiler, tubular boiler, return tubular boiler, low-pressure boiler. General description of the accessory parts. Fire-tools. Working of a boiler. Principal dimensions of return tubular boilers, two types. Rectangular boiler. Arrangement of boilers.

3.-Details of construction of boilers and their parts.-Mode of connecting the fixed pieces; bolts, viz, tap-bolts, stud-bolts, dowels, rivets. Boiler-plates; mode of assemblage. Angle irons.

Dead plates, grates, bearer-bars, lugs, bridge-walls. Diagonal bracing, longitudinal and bridge-bracing. Man-hole plates. Tubes; their fastening on the tubesheet, ferules; beading: movable tubes. Langloir's system. Gautelme's system. Toscer's system. Fixed and movable pipes. Natural draught produced by the smoke-pipe. Forced draught. Check-valves. Glass water-gauge; putting the glass tube in place. Gauge-cocks Blow-off cock. Safety-valve. Dimensions and load of a safety-valve. Safetyvalve for small boilers at high pressure. Atmospheric valve. Stop-valve. Communicating-valve. Dry pipes and superheaters.

Pipes and valves. Joints with fixed and movable flanges. Soldered and riveted flanges. Slip-joint. Single-way, two-way, and four-way cocks. Hollow-plug cock. Sea-cocks. Kingston valve.

4.-Cylindrical boilers.-Return tubular and high-pressure boiler. General description of boiler with appendages. Arrangement of brace-tubes. Method of joining the boiler-plates. Principal dimensions.

5.-Short description of the principal types of boilers in use.-Tubular boiler. Sideflue boiler. Cylindrical boiler for launch. Belleville boiler for launch; working of this boiler. Details of feed regulator.

over.

V.

Management of engines and boilers.

1. Working the engine.-Preparations for starting. Blowing through and turning Direct blowing through of the condenser. Starting. Increasing or reducing speed. Final stop. General care to be given to the engine while in motion.

2.-Fuel and combustion.-Calorific power. Evaporative power. Air of combustion. Space occupied by a given weight of coal. Manner of burning of the fuel. Conditions of good combustion. Imperfect combustion. Smoke, soot, clinker; slag.

General character of coal; coal, properly so called; rich and poor coals; hard or compact coals. Anthracite. Lignite. Conglomerate or pressed fuel. Briquettes.

3.-Management of fires.-Priming the furnaces. Lighting. Care of the fires while the engine is in motion. Increasing and moderating fires. Banking fires. Forcing fires. Hauling fires.

4.-Feeding and blowing.-Filling the boilers. Keeping up a constant level. Feeding during a stop. Salts in solution in sea-water. Action of the salt in the boiler.

Deposit. Measure of density; salinometer; testing salinometer. Effect of deposits; means of prevention; blowing off. Losses occasioned by it. Regulation of the blowing off. Emptying the boilers.

5.-Pressure; production of steam.-Keeping up the pressure. Increasing and diminishing pressure. Coal consumed, (1) in terms of the evaporation per given weight of coal; (2) per unit area of grate in a given time.

6.-Accidents.--Foaming: causes; effects; remedies; means of prevention. Priming: causes; effects; remedies; means of prevention. Leaks: their consequences. Plugging a leaking tube. Dangerous lowering of the water level in the boilers; measures to be taken.

7.-Cold testing of boilers: object and methods.

SECOND YEAR.

I.

Principal types of ordinary engines in use, of Woolf's or compound engines, and of boat

engines.

Oscillating paddle engine. Compound inverted-cylinder engine. Woolf's threecylinder back-acting engine. Inverted-cylinder non-condensing launch engine.

Silent launch engines.

II.

Description and details of various parts of the machinery.

1.-The cylinder and its appendages.-Cylinder; valve-seat; ports; bottom; cover. Clearance. Ratio between the stroke of the piston and the diameter of the cylinder. Steam-jacket; lagging.

Cylinders and steam-passages of Woolf engines. Continuous-expansion engine. Compound engines, with cranks at 90°. Three-cylinder engines, with cranks at 90° and 135°. Piston-rod stuffing-boxes for horizontal and vertical cylinders. Laying up the packing. Stuffing-box capable of adjustment while under way. Cylinder relief-valves. Blow-through cock. Ordinary balance-pressure lubricator. Thibaut's lubricator. Roscoët's lubricator.

2.-Steam piston, packing, rods.-Spider of piston; piston-rings; follower. Anti-friction piston-rings. Piston-rods; fitting of the rod in the piston and in the crosshead. Trunks; their adjustment with the piston. 3.-Slide-valves.-Review of the classification. Ordinary three-ported slide-valve. Object of equilibrium packings. Box-valve on Mazeline's system. Doubleported slide-valve. Dupuy de Lôme's long D-valve. Rectangular long D-valve of Indret. Relative merits of different methods of distribution. 4.-Starting and reversing gear.-Review of the classification. Mazeline's starting gear. Stephenson's link; explanation of the action of the link.

5.-Valves: regulators and apparatus of variable expansion.-Throttle-valve. Stopvalve. Throttle-valve in boat engines.

Governors: two classes. Adaptability for marine engines. Conditions that must be fulfilled by a governor used in a marine engine. Farcot's governor: description, conditions of equilibrium, and mode of action. Servo-moteurs: geometric description of a servo-moteur applied to an engine.

Apparatus for variable cut-off; their use. Review of the classification. Expansion by means of gridiron-valve and adjustable eccentric. Meyer's expansionvalve. Expansion by means of a butterfly-valve moved by a fixed eccentric of variable throw. Expansion-valve regulated by a link.

6. The condenser and its parts.-Analysis of the processes of condensation by injection and of surface condensation. Weight of the injection water; temperature of jet condensation. Weight of cold water in surface-condensers; temperature