A Treatise on Mine-surveying |
From inside the book
Results 1-5 of 44
Page 2
... screws acting on horizontal and vertical cog - wheels . It was hollowed out , and contained a metal tube , at right angles to which were glass cylinders at each end of the beam . The cylinders had special covers made of metal plate ...
... screws acting on horizontal and vertical cog - wheels . It was hollowed out , and contained a metal tube , at right angles to which were glass cylinders at each end of the beam . The cylinders had special covers made of metal plate ...
Page 31
... screw - joint in the middle , and a set of extra points is provided to screw on , when the workings are low . The dial is connected with the tripod by means of a ball and socket joint , which consists of a ball at the end of a covered ...
... screw - joint in the middle , and a set of extra points is provided to screw on , when the workings are low . The dial is connected with the tripod by means of a ball and socket joint , which consists of a ball at the end of a covered ...
Page 44
... may be made of a brass rod about 7 inches in length , provided at its lower end with a screw and at the top with a very thin plate of brass about 2 inches long and 1 inch broad , so arranged that it 44 MINE - SURVEYING .
... may be made of a brass rod about 7 inches in length , provided at its lower end with a screw and at the top with a very thin plate of brass about 2 inches long and 1 inch broad , so arranged that it 44 MINE - SURVEYING .
Page 47
... screw of the upper plate until it also passed the horizontal wire . If the theodolite is set up on a fixed point , and if the terres- trial object , the azimuth of which is determined , is also a secure point , a further marking - out ...
... screw of the upper plate until it also passed the horizontal wire . If the theodolite is set up on a fixed point , and if the terres- trial object , the azimuth of which is determined , is also a secure point , a further marking - out ...
Page 58
... screw is turned , two marks , made opposite to each other , one on the projecting portion of the compass - box , and the other on the plate , will separate . Their angular distance apart is measured by means of a vernier , which may be ...
... screw is turned , two marks , made opposite to each other , one on the projecting portion of the compass - box , and the other on the plate , will separate . Their angular distance apart is measured by means of a vernier , which may be ...
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Common terms and phrases
accuracy accurate adjusted back-sight base-line bearing bore-hole brass calculated centre chain City Guilds clamped clinometer coal colliery collimation colour compass compass-box contour lines cord corner cosec cotan cross-wires curve determined direction distance employed equal error fathoms feet fixed fore-sight glass graduated ground height hole horizontal circle inches inches in diameter inclination instrument intersection latitude length lode magnetic bearing magnetic meridian magnetic-needle marked means measured method metres mine-surveying miner's dial mines needle observations obtained offsets Ordnance Survey parallel parallel ruler perpendicular placed plane plate plotting plumb-bob plumb-line plummet position protractor represented right angles safety-lamp scale seam shaft side Silver King spirit-level square staff station station-line strike and dip surface surface-surveys survey tacheometer tacheometry taken tangent screw telescope theodolite transit-theodolite traverse triangle tripod tube underground vernier vernier-plate vertical angles wire yards zero