A Treatise on Mine-surveying |
From inside the book
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Page 2
... shown by the fact that such problems are fully discussed by Hero of Alexandria ( B.C. 285-222 ) , several of whose works are extant . The greatest advance in survey practice made by Hero was his invention of the diopter , a sighting ...
... shown by the fact that such problems are fully discussed by Hero of Alexandria ( B.C. 285-222 ) , several of whose works are extant . The greatest advance in survey practice made by Hero was his invention of the diopter , a sighting ...
Page 20
... shown by joining lines in a way similar to the form which they present on the ground . The following example shows the manner in which the field- notes may be entered in the survey of a triangular piece of ground : - From B 687 to D ...
... shown by joining lines in a way similar to the form which they present on the ground . The following example shows the manner in which the field- notes may be entered in the survey of a triangular piece of ground : - From B 687 to D ...
Page 25
... shown by the following averages : - INSTRUMENT . MEAN SPEED PER MINUTE . ASSISTANTS . Absolute . Per Assistant . Feet . Feet . Rods ,. 2 45 22 Chain , 2 59 29 Steel band , 2 65 32 Field - compasses , 1 85 85 CHAPTER III . THE MINER'S ...
... shown by the following averages : - INSTRUMENT . MEAN SPEED PER MINUTE . ASSISTANTS . Absolute . Per Assistant . Feet . Feet . Rods ,. 2 45 22 Chain , 2 59 29 Steel band , 2 65 32 Field - compasses , 1 85 85 CHAPTER III . THE MINER'S ...
Page 29
... shown in Fig . 9 , the points are replaced by a fine etched line , representing the mag- netic axis . Fig . 8 . Fig . 9 . Fig . 10 . The needle is drilled through in the centre , and carries above the aperture a hollow brass cap , lined ...
... shown in Fig . 9 , the points are replaced by a fine etched line , representing the mag- netic axis . Fig . 8 . Fig . 9 . Fig . 10 . The needle is drilled through in the centre , and carries above the aperture a hollow brass cap , lined ...
Page 33
... shown the sights are carried by an outer ring concentric with the dial . This arc was invented in 1850 by John Hedley , H.M. Inspector of Mines . In Fig . 12 . If The side arc with sights attached to it should be avoided . the sights ...
... shown the sights are carried by an outer ring concentric with the dial . This arc was invented in 1850 by John Hedley , H.M. Inspector of Mines . In Fig . 12 . If The side arc with sights attached to it should be avoided . the sights ...
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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