Solid Geometry. (40.) *44. The given triangle represents the plan of one of the isosceles triangles which make up an octagon. Complete the plan and determine the side of the octagon. *45. The given figure represents in isometric projection three equal rods, ab, cd, ef (2" long), such that ab and ef are at right angles to cd, and the plane containing ab and cd is at right angles to ef. Draw the plan and any elevation of the rods, a and e being in the horizontal plane, and cd inclined at 30°. (40.) *46. aa, bb, are the horizontal traces, and ii is the plan of the intersection of two planes at right angles to each other. Determine a third plane cutting them in two lines including an angle of 50°, and having lm as its horizontal trace. (45.) *47. Draw the plan of the inscribed sphere of the given triangular pyramid. Unit 0.1". (45.) #48. A series of pairs of lines drawn from Ρ and q meet on the surface of the given sphere, and each pair makes equal angles with the normal at the point of meeting. Trace the locus of the point of meeting for a short distance, and determine the two lines fulfilling the above condition, and the sum of whose length is the minimum possible. (55.) *49. The plan of a right cylinder is given. A sphere 23" in diameter rolls on the horizontal plane always touching the cylinder. Draw the plan of the locus of the point of contact. (50.) 50. Two equal right cones, height 12", diameter of base 2", have a common vertex. One cone rolls upon the other which stands on the horizontal plane. Draw the plan of the curve described in one revolution by a point on the base of the rolling cone. (50.) *51. Determine the outline of the shadow cast by the table on the horizontal plane; the rays of light being parallel to the one, the plan and elevation of which are given. (55.) *52. Draw a perspective view of the table. The ground line of the picture plane is the line ab. The station point is opposite, and 54" from a. The horizon is 24 times the height of the table. (60.) Graphic Statics. 53. Forces having the given magnitudes and directions act on the horizontal beam AB. Determine the point about which the beam will balance. (40.) *54. A load w of 250 lbs. is suspended from the end A of a beam AB supported at B. (1) Determine the position which must be given to a tie AC, such that it will hold AB in the given position, and that the stress it will have to bear has the same intensity as that in AB. Write down the amount of this stress. (2) What position must be given to AB and AC such that the stresses in both are 12 times the load w? (40.) SUBJECT II. MACHINE CONSTRUCTION AND DRAWING. EXAMINERS, PROF. T. A. HEARSON, M. INST. C.E., AND J. HARRISON, Esq., M. INST. M.E. GENERAL INSTRUCTIONS. If the rules are not attended to, the paper will be cancelled. You may take the Elementary, or the Advanced, or the Honours paper, but you must confine yourself to one of them. Put the number of the question before your answer. You are expected to prove your knowledge of machinery, as well as your power of drawing neatly to scale, You are therefore to supply details omitted in the sketches, to fill in parts left incomplete, and to indicate, by diagonal lines, parts cut by planes of section. Where more than one view of the same subject is drawn, no credit will be given unless the different views are properly projected one from the other. The centre lines should be clearly drawn. The figured dimensions need not be inserted. Your answers should be clearly and cleanly drawn in pencil. No extra marks will be allowed for inking in. All figures must be drawn on the single sheet of paper supplied, for no second sheet will be allowed. The value attached to each question is shown in brackets after the question. A full and correct answer to an easy question will secure a larger number of marks than an incomplete or inexact answer to a more difficult one. Your name is not given to the Examiners, and you are forbidden to write to them about your answers. You are to confine your answers strictly to the questions proposed. A single accent (') signifies feet; a double accent (") inches. The examination in this subject lasts for four hours. First Stage or Elementary Examination. INSTRUCTIONS. Read the General Instructions above. Answer briefly any three, but not more than three, of the following questions, and draw two, but not more than two, of the examples. Questions. (a.) Give sketches showing how the cutting tool of a lathe or other machine is secured in place. (6.) (b.) Make a sketch of a stud; describe how it is screwed into place, and state some circumstances under which it is used in preference to a bolt. (6.) (c.) Give sketches showing one method of attaching the valve rod to an ordinary slide valve. (6.) (d.) Sketch a connecting rod end with strap, gib, and cotter. Explain the use of the gib. (10.) (e.) Explain the use of the quadrant for change wheels for a screw-cutting lathe shown in example 1, by making a sketch showing it in place on a lathe with wheels in gear. (10.) (f.) Sketch one form of hanger suitable for supporting mill shafting. (10.) Examples to be Drawn. 1. Quadrant for change wheels for screw-cutting lathe. Draw the two views shown. Scale half size. (35.) 2. Crank-shaft. Draw the two views as shown, partly in section. Scale full size. 1 (35.) 3. Ball bearing for Tricycle. Draw the two views as shown, partly in section. Draw full size. Second Stage or Advanced Examination. INSTRUCTIONS. Read the General Instructions above. (35.) Answer briefly any three, but not more than three, of the following questions, and draw the example given. (g.) Give sketches and a description of an adjustable spanner. 10 IL-MACHINE CONSTRUCTION AND DRAWING. (h.) Show two forms of continuous lubricators for bearin ELE describe their action. (k.) Give sketches of a mortice spur wheel showing the f the rim and of the teeth, and the method of fixi latter. ( (1.) Make sketches showing the method of joining the pla a cylindrical boiler at a point where a longitudinal meets a ring joint. (2 (m.) What materials should be used in the construction< excentric shown in diagram E? How is the wear ( excentric taken up? State the effect of this adjust on the length of the rod, and how it may be correct (2 (n.) The wheels of the back gear of a lathe have 50 an teeth respectively, the pitch being the same in e The smaller wheel on the lathe mandril has 18 te what number of teeth should the larger wheel have ?t? the mandril makes 100 revolutions per minute with back wheels out of gear, how many revolutions per mir will it make with the back gear in, the position and sp of the belt being unaltered ? Example to be Drawn. (20. Allan's Straight-link Reversing Gear for Steam Engine. Dr. the two views shown, and add an end section through the cen: of the link. Draw to a scale of full size. (140.) Read the General Instructions above. You are permitted to answer only eight of the following questions. The sketches required in answer to these questions may be in pencil, and need not be drawn to scale, but should be neat and in good proportion. The written answers must be in ink, and may be written on foolscap paper, which can be obtained on application to the superintendents of the examination. Each sketch should be made in immediate connection with the answer to which it refers. |