150
THE HONGKONG GOVERNMENT GAZETTE, MARCH 11, 1910.
307.
How many cylinders are generally used in oil-motors? What kind of pistons are fitted? How frequently (measured in revolutions) is explosion per cylinder effected? How is explosion in the cylinder carried out ?
308.
Describe how an oil-motor is started. If starting prove difficult, where would you chiefly look for defects? How is piston speed modified? How is the speed of vessel varied? How is reversing effected ?
309.
Before examining an oil-motor with a naked light, what steps should be taken for safety's sake?
310.
How frequently should an oil-motor, working 12 hours a day, be opened up for exami- nation, cleaned, and its parts readjusted? What difficulty arises when the internal parts become foul with carbonized oil ?
NOTE.--Questions isolated from their context should be read in the light of the context. Thus the "sparking" referred to in question 283 relates to the sparking in an electric lighting circuit on board ship. See question 281.
Appendix C.
EXAMINATION IN ROUGH WORKING DRAWING FOR A FIRST CLASS ENGINEER'S CERTIFICATE OF COMPETENCY.
1. The regulations of the Board of Trade in regard to the qualifications of a candidate. for a First Class Engineer's certificate of competency specify that,-
"He must be able to make rough working drawings of the different parts of the
engines and boilers.
"He must be able to state the general proportions borne by the principal parts of
the machinery to each other."
2. In accordance with these clauses, a candidate for a First Class Certificate is required to make a rough working drawing of the parts. An Engineer who has been some years in charge of marine engines and boilers ought to have familiarly in his mind the general con- struction of at least one set of engines and boilers, say that set he was last with. Fine drawing is not expected, and in the proportions of the parts a wide margin will be allowed d; absurd dimensions will be failure in practical knowledge.
3. The drawing must, however, be practically a working drawing, giving a sufficient number of views to show the parts fully-sections, plans, or elevations, just as the candidate would require to be supplied to him if he had to make the parts to the design of another
person.
4. A clear hand sketch showing the constructions completely, and fully dimensioned, will be accepted if the candidate prefers this alternative.
5. A portion only of the parts specified may be accepted in place of the whole, if that portion is sufficient to show that the candidate has a good practical idea of the construction of the parts, and a fair notion of their general proportions or dimensions.
6. Candidates are hereby cautioned not to put on paper what they have not fully considered, and deliberately intend to be understood, as their statement of what they know about the construction of any part required.
7. The statements given in by a candidate may be in themselves, apparently, of little importance, but, as sample material from which the state of the candidate's knowledge of engines and boilers is to be inferred, every detail which is glaringly inconsistent with a sound knowledge of the use of the part, or in which an essential consideration has evidently been overlooked, is an important element in the description which the candidate is giving of his own qualifications.