Senior Examinatirm Papers, 1891. 
415 
EXAMINATION IN AGRICULTURAL ENGINEERING. 
Maximum Number op Marks, 200. Pass Number, 100. 
Wednesday, May \ith,fTom 10 a.m. till \ p.m. 
N.B. — Not more than half the qnestimis should he attempted, 
1. Explain what is meant by elastic limit and ultimate stress in 
materials. 
2. What conditions are to be observed in designing surfaces which are to 
work on each other, as, for example, axles in their bearings, or the slide blocks 
guiding the piston-rod cross-heads of steam engines on their slides ? 
3. Describe the construction and the mode of graduating an ordinary 
mercurial thermometer, and state what is meant by the absolute zero of tem- 
perature. 
4. Explain what is meant by " temperature," by " specific heat," and by 
" latent heat." 
5. Explain the cause of the difference of specific heat of gases at constant 
volume and at constant pressure. 
6. Explain and illustrate by sketches the action of wind upon the sails of a 
windmill. 
7. Sketch an ordinary single-acting 3-inch hand suction and force pump, 
such as is commonly used in weUs or for domestic supply. Mark the principal 
dimensions. 
8. What is the usual method of freeing water from mechanical impurities 
and rendering it fit for domestic use ? Sketch and describe an installation to 
yield 3,000 gallons per 24 hours. 
9. Describe the process by which the potential energy in coal is converted 
into useful work by means of a non-condensing steam engine. 
10. A condensing steam engine is required to work up to 30 indicated 
horse-power measured in the cylinder. Calculate the quantity of feed and of 
condensing water required per hour. You may assume such boiler pressure, 
temperatures of water, and eflSciency of the engine as you think will probably 
obtain in a good engine. 
11. What is the difference between a gas and a petroleum engine 1 
12. Sketch carefully and dimension as far as you can a 12-inch metallic 
piston. 
13. Describe the system of steam ploughing by means of two engines and 
a balance plough. 
14. Sketch and describe a horse-hoe. 
15. What is the use of a horse-rake ? Describe its action, illustrating your 
description by sketches. 
16. Sketch an ordinary cart-wheel, and describe its various parts. 
17. Describe a chaff-cutter, and illustrate your description by sketches, and 
explain the safety appliances. 
18. Show how two lay shafts, say 10 feet apart and crossing each other at 
right angles, can be driven by a flat belt so that there will be no tendency of 
the belt to come off. State whether the direction of revolution is a material 
factor in the arrangement. 
