9. Discuss fully, with illustrative sketches, the various arrangements in use for generating by means of steam power continuous and alternating electric currents for lighting and power purposes in large cities. 10. Write an Essay on the utilization of water power by electric transmission to long distances. APPLIED MECHANICS III. Not more than Two questions are to be attempted. The drawings should be carefully done in pencil on cartridge paper, and to the scales indicated. All necessary dimensions should be clearly shown, and parts in section should be properly hatched. 1. Design and make an outline drawing of the shell of a steel Lancashire boiler to suit the following conditions Length 30 ft., diameter 7 ft., pressure (abs)=100 lbs. per sq. inch, factor of safety 5. Scale of drawing, in. 1 foot. Supply also detail drawings showing full particulars of the seams and joints, and of the means of staying the ends of the boiler. Scale, 2 in.=1 foot. Supply a list of the necessary fittings for the boiler. 2. Design a connecting rod and its brasses suitable for any of the engines in the laboratory; show clearly the arrangements for adjusting the brasses. Length of rod=3 ft. ; maximum diameter of section=2 in. Scale, 3 in. 1 foot. 3. Make an accurate working drawing from the accompanying rough sketch. (See attached sheet.) APPLIED MECHANICS IV. Not more than ONE question from each section (A, B and C) are to be attempted. A. 1. In a trial of a Worthington steam pump the following estimations were made from direct measurement: Coal used per hour Estimated heat value of one pound of coal Feed water per hour =456 pounds. =14,880 B.T.U.'s. Temperature of feed water =50° F. Boiler pressure (by gauge) 60 pounds per square inch. ture =307° F. Calculate the efficiency of the boiler, of the steam in the engine, of the mechanism of the engine and pump, and of the total pumping process. Also estimate the various quantities of heat which are not utilized, and determine what amount of the total heat expended is not accounted for in the above observations. 2. Describe and discuss any extensive series of tests on the steam engine with which you may be acquainted. Explain clearly the objects aimed at in the investigation, and summarize the results obtained. B. 3. Write an Essay on modern developments of pumping machinery for water supply and sewerage purposes, and illustrate it by an outline of a scheme to pump 5,000,000 gallons a day to a distance of 300 miles and a height of 1,500 feet over an undulating country. 4. An air compressor consists of two steam and two air cylinders, each air cylinder being tandem to its steam cylinder. There are two connecting rods and two cranks at right angles on one shaft. The steam cylinders are provided with an inter-heater and the air cylinders with an intercooler. Discuss fully the action of this machine, state exactly the function of the fly-wheel, propose dimensions for the steam and air cylinders, and drow their indicator diagrams, the steam and air pressure being both 100 lbs. per square inch above the atmosphere, and the required supply of cold air being 1 cubic foot per revolution. C. 5. A plant for lighting the streets of a city consists of 3 boilers, 3 engines, and 12 dynamos, the total indicated horse power of the whole being 1,000. The engines make 80 revolutions per minute and the dynamos 800. Show how you would arrange this plant, and design the steam piping and transmissive machinery, it being essential that no ordinary accident shall disable more than one-third of the plant at one time, economy of space not being a paramount consideration. 6. It is required to supply current to 4,000 16-candle power incandescent lamps in shops and private houses scattered over 10 square miles of country. Sketch out the general arrangements of a lighting station and system of aërial conductors for this purpose, giving dimensions and other numerical particulars of the plant required. Special attention is to be given to the protection of the dynamos from lightning, and to the necessity of not interfering with the telephones of the district. Good water for boiler purposes is obtainable from the town mains, and a tidal river which is often salt and polluted with sewage flows past the station. Give all particulars you can as to the plant, including the probable cost of running the station, fairly good coal being available at 14s. a ton. 7. It is required to pump 10 cubic feet of water per second from a river to a reservoir 100 feet above the river and half-amile distant. The river rises 20 feet during ordinary floods, and 40 feet at intervals of about 30 years. The banks of the river are rocky, and have an average slope a of 1 in 6. Give outline drawings and full particulars of steam pumping plant, including probable cost of installing and working. SURVEYING. (FOR MINING ENGINEERS.) See the paper set in the Third Year. MATHEMATICS. HONOURS. The same papers as those set in the Third Year of Arts. SURVEYING. THREE questions in each section to be attempted, I. 1. In survey, certain errors tend to accumulate, others on the contrary, to cancel one another. (a) Give examples of these in connection with the measurement of angles and that of lines: (b) explain why some errors cancel one another, and what is the probability of their doing so when they are of the same average magnitude: (c) Distinguish between "mistake" and " error," and briefly shew how mistakes may sometimes be localized. 2. Distribute the errors and give the corrected coördinates of the following traverses forming a closed circuit; (b) calculate the corrected double longitudes of each line; and (c) shew what products will give the area enclosed by the circuit, and calculate the area. Line. Distance. Weight. Northing. Southing. Easting. Westing. (NOTE-Express the quantities, to be multiplied into each other for the area, to nearest whole link.) 3. (a) How can the value of the divisions of a level tube be ascertained? (b) If these values change irregularly with variations of temperature, can the indications of the A bubble be relied upon? (e) Shew that whatever the relation between the axis of the level tube, and the collimation line of the telescope, the true difference of level between two points can be ascertained. (d) Briefly describe the adjustments of the level, and the sources of error in levelling. 4. Write an essay on plane-table and telemetric surveying, discussing several problems in the former element, and giving formula deduced by the theory of stadia measure ment. 5. (a) Shew fully by diagrams and explanations how with steel riband and theodolite, etc., a circular curve would be set out, an ellipse, a parabola, a graduated curve, and a curve of adjustment. (b) How are cross-overs and turnouts set out in lines of railway? (c) Discuss briefly the relative merits of a curve of varying "degree" and a cubic parabola, in running from a straight on to a curve of constant radius. 6. How can the volume of earth-work be ascertained (a) in lowering or raising a surface generally, (b) and in making cuttings or embankments. (c) Calculate the following example for quantity of cutting and quantity of filling: Width of section of road BE be 64 feet: BC = bc =32 feet. Length of section of road, initial to terminal section = 100 feet. IHDG and ihg are the natural surfaces. IBCDEG and ibceg are the formed surfaces. = IA = AB 16 feet; CH 10 feet; FG EF = 12 feet. = |