MECHANICAL ENGINEERING. FIRST PAPER. The Board of Examiners. Only FIVE questions to be attempted. 1. It is required to pump water from a well 50 feet deep by the power of one good horse. Sketch out the arrangement necessary, give all the dimensions you can, and compute the amount of water that can be raised in an hour. 2. A simple wooden water-wheel is required for a fall of 20 feet, and a discharge of 2 cubic feet per second. Sketch the general arrangement, compute the power available, and show gearing to connect the wheel with a shaft making 60 revolutions per minute, giving as many dimensions and details as you can. 3. Propose suitable dimensions for the cylinder of a steam-engine to exert 20 actual horse-power, with steam at 100 lbs. per square inch, and at 100 revolutions per minute, cutting off at halfstroke, and design a suitable slide valve and eccentric. 4. A non-condensing steam-engine, using steam at 50 lbs. per square inch, has its cut-off at stroke, its exhaust at, and compression at Draw the indicator diagram, and discuss its peculiarities. 5. Discuss the effect upon power obtained and steam consumed obtained by adding a good condenser to the above engine. 6. A simple pendulum governor has arms of 14 inches in length. In what position will it stand at 60 and at 70 revolutions per minute? Discuss the effect upon this governor of loading it, as in Porter's governor, with a weight 10 times that of each pendulum ball. 7. Supply simple rules for computing the horse-power that can be transmitted by shafts, belts, and ropes of given size. 8. Supply dimensions of a hydraulic accumulator to store up 1,000 foot tons at a pressure of 1,000 lbs. per square inch. Make a detailed sketch of the whole arrangement. MECHANICAL ENGINEERING. SECOND PAPER. The Board of Examiners. Not more than FIVE questions to be attempted. 1. Make a neat sketch of a modern water-tube boiler suited for high pressures, and discuss its advantages as compared with other forms of boiler. 2. Draw the indicator diagrams, and compute the probable indicated horse-power of a tandem compound engine, having cylinders 15 and 26 inches in diameter, 3 feet stroke, 80 revolutions per minute, steam 150 lbs. per square inch, and vacuum 25 inches. 3. Make a neat section of one steam cylinder, with piston, slide valve, and valve gear of a Worthington steam pump of the simplest kind, and explain the action of the various parts. 4. Make a neat drawing of a modern form of gasengine, discuss its action fully, and give numerical particulars as to its performance. In what way does such an engine differ from those made twenty years ago? 5. Write a short essay on centrifugal pumps, illustrated by a sketch of such a pump suitable for raising 500 gallons of water per minute 20 feet high. 6. Explain fully, with sketches, the meaning of the following terms:-Alternator, exciter, transformer, parallel working, voltmeter, ammeter. 7. A stream supplies 100 cubic feet of water per second, falling 50 feet. Propose a scheme for utilizing this for supplying electricity to arc lamps for street lighting, giving sketches and numerical particulars. HYDRAULIC AND SANITARY ENGINEERING. FIRST PAPER. The Board of Examiners. The sketch shows a cross-section of the site of a proposed dam. Trial pits have been sunk as shown. The granite on the left bank is a good deal fissured, and the upper portion of the whole of the granite for a depth of about 3 feet throughout is considerably decomposed, below this it is quite sound. The area of the watershed is 11 square miles in mountainous country, of which the average annual rainfall is 30 inches. Design the dam, and prepare an estimate of its cost, allowing £2 per cubic yard for concrete, 10s. for clay, and 1s. for ordinary earthwork. HYDRAULIC AND SANITARY ENGINEERING. SECOND PAPER. The Board of Examiners. 1. Design a hydraulic ram to raise 10 gallons of water per minute through a height of 200 feet, delivering it through a 1-inch pipe into a tank 20 chains from the ram. There is a dam 6 feet high across the creek from which the supply is drawn, and the fall of the creek-bed is 10 feet per mile. Make neat sketches, with figured dimensions, of the more important details. 2. A B C are three points such that AB is 30 chains, BC is 40 chains, and CA is 50 chains. It is required to carry a 4-inch main from A to C and a 4-inch branch from the main to B in the most economical manner. Determine the route of the main and the position of the branch, and give the cost of the work, allowing £7 per chain for the piping laid complete. HYDRAULIC AND SANITARY ENGINEERING. THIRD PAPER. The Board of Examiners. Give a full description of the Werribee Sewage Farm, with sketches of the various works used in the distribution of the sewage and the drainage of the land. Indicate clearly the nature of the difficulties to be overcome in distributing the sewage, and, in the event of your proposing to modify any of the arrangements, show what alternative methods you would adopt. |