Handbook for Government Surveyors |
From inside the book
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Page 15
... vernier are now noted , and observations are continued invariably towards the right hand , so that east is denoted by 90 ° , south by 180 ° , west by 270 ° , and so on until all piles visible throughout the entire sweep of the horizon ...
... vernier are now noted , and observations are continued invariably towards the right hand , so that east is denoted by 90 ° , south by 180 ° , west by 270 ° , and so on until all piles visible throughout the entire sweep of the horizon ...
Page 18
... vernier plate , the upper part of the instrument should now be turned half way round , the telescope reversed and directed to the star again , and the angle read a second time ; or should it be required only to peg down the star , the ...
... vernier plate , the upper part of the instrument should now be turned half way round , the telescope reversed and directed to the star again , and the angle read a second time ; or should it be required only to peg down the star , the ...
Page 103
... vernier should be clamped at the last angle used : then , by reading to the left the angle between the nearest peg and the former position of the instrument , a check angle is obtained , and by reversing the telescope everything is in ...
... vernier should be clamped at the last angle used : then , by reading to the left the angle between the nearest peg and the former position of the instrument , a check angle is obtained , and by reversing the telescope everything is in ...
Page 125
... vernier is now read , the index error applied , and the result halved , after which the correction for refraction has to be subtracted from it . To avoid parallax in reading off the angle , the light should be held in a line with the ...
... vernier is now read , the index error applied , and the result halved , after which the correction for refraction has to be subtracted from it . To avoid parallax in reading off the angle , the light should be held in a line with the ...
Page 126
... vernier plate and bring it round until the telescope is over two of the levelling screws ( say pointing north ) , bring the bubble of the telescope to the centre of its run , turn the vernier plate half round ( say.pointing south ) ...
... vernier plate and bring it round until the telescope is over two of the levelling screws ( say pointing north ) , bring the bubble of the telescope to the centre of its run , turn the vernier plate half round ( say.pointing south ) ...
Common terms and phrases
ADELAIDE adjustment aneroid azimuth Barometer bubble calculated camp chain chainage clamp colat column Const corresponding cosec cosine cross hairs declination degrees diameter diff difference of longitude dist divided DUMPY LEVEL earth east elongation equal equator EXAMPLE formula gives GOVERNMENT PHOTOLITHOGRAPHER Height in Feet Hill horizontal angle hour angle hypsometer inches index error instrument intersection length logarithm Mean Refract merid meridian passage method miles and decimals mins minutes multiplied Nautical Almanac noted number of seconds observed altitude observed angles offset pegs plate point of Aries polar distance prime vertical radius of curvature readings right ascension sextant side sidereal sight sine spherical excess square root star star's stations Steel Tape subtract sun's centre survey surveyor taken tangential angles telescope Temp theodolite Thermometer triangle true bearing true meridian vernier zenith distance ΙΟ
Popular passages
Page 18 - The light reflected from the paper will show the cross hairs in the telescope of the theodolite. Then, let the vertical spider's line be brought exactly upon the polestar, and, if it is an eastern elongation that is to be observed, and the star has not yet reached the most easterly point, it will move from the line toward the east, and the reverse when the elongation is west. At the...
Page 134 - Sun from the meridian, at the instant when the true point of intersection of the ecliptic and equator (called the first point of Aries) is on the meridian of Greenwich ; and as the distance of the first point of Aries from the meridian, at the instant the mean Sun is on the meridian, is denominated Sidereal Time at Mean Noon, this may, by analogy, be termed the Mean Time at Sidereal Noon. It is the time...
Page 113 - Act contained shall take away or affect any right of action or other remedy which any person may have in respect of any loss or damage occasioned by any fire or for any trespass committed.
Page 134 - ... it may also be regarded as the arc of the equinoctial intercepted between those circles. It is measured toward the west as a positive direction through...
Page 62 - ... perfect the exhaustion. The actual movement at the centre of the elastic box, from whence the indications emanate, is very slight ; but this is increased 657 times at the point of the hand ; so that a movement to the extent of...
Page 122 - W ) v 2 (W) equal the sum of the weights for the mean of each night. The observations for longitude were submitted to Professors GP Bond and James Major for computation. Table "B...
Page 19 - ... line of sight not being at right angles to the axis of vertical motion 18.
Page 28 - Observed horizontal angle 77° 45' between Canopus and /3 Tri. Aus., at opposite elongations, pol. dis. 37° 22
Page 30 - ... will be the logarithm of the number of seconds and decimals in the arc — that is, no'oo.
Page 134 - Right ascension of the meridian is the hour angle of the first point of Aries.