Calendar: 1871-1872 Page 545

APPLIED SCIENCES 545 If the first angle was 108" 16' what would he the second and third for the first to he correct What would they be if the first was 145 38 and what if 230 6' Describe the spirit-level and the level staff The sides of field are 420 380 and 320 feet respectively the field is let for £6 How much is that per acre Convert 10 acres roods 28 perches into square feet For what surveying work would you use the theodolite for what the circumferenter and when would you with advantage dispense with both When would you use the spirit-level and when the theodo- lite to take sections Given rectangular field containing acres one of the sides of which is chains larger than the other What would be its acreage after taking off path of 15 feet wide inside all round iomttriral Staining THIRD YEAR Construct regular polygon of seven sides on line 1" long Inscribe regular octagon in circle of 1"25 radius Draw semi-ellipse major axis 35 long and horizontal semi-minor axis 1"25 find the focii of the ellipse Supposing the semi-ellipse to represent the curve of an arch show method of setting out the lines of the voussoirs in any part of the curve will be sufficient Draw triangle its sides 2"4 "-l and 3" in length and regular hexagon equal to it in area pyramid axis 2"'5 base hexagon of 1" side has its apex in the horizontal plane and axis vertical plan and elevation required Its shadow on the horizontal plane cast by parallel rays inclined at 55 direction of their plans at pleasure plane is shown by its traces to be inclined at 35 and its intersection with another plane at right angles to it is inclined at 25 show traces of the other plane