The Theory and Practice of Surveying: Containing All the Instructions Requisite for the Skilful Practice of this Art |
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Page 71
... lay the line C , from A to C ; and D , from C to D ; and join the points B and D by the line BD ; through C draw CE parallel to BĎ ( by prob . 8. ) so is E the point of division . For , by cor . 1. theo . 20. AC : AD :: AE : AB . Or , C ...
... lay the line C , from A to C ; and D , from C to D ; and join the points B and D by the line BD ; through C draw CE parallel to BĎ ( by prob . 8. ) so is E the point of division . For , by cor . 1. theo . 20. AC : AD :: AE : AB . Or , C ...
Page 72
... lay it on that circle from a to b , through △ and b , draw the line AbC ; and the angle A will be an angle of 45 degrees , as required . If the given angle be more than 900 , take its half ( or divide it into any two parts less than 90 ) ...
... lay it on that circle from a to b , through △ and b , draw the line AbC ; and the angle A will be an angle of 45 degrees , as required . If the given angle be more than 900 , take its half ( or divide it into any two parts less than 90 ) ...
Page 80
... laid down on the best six - inch brass sectors . But as the principles are the same in all , and the differen- ces little more than in the number of subdivisions , it is to be presumed that no difficulty will occur in the application of ...
... laid down on the best six - inch brass sectors . But as the principles are the same in all , and the differen- ces little more than in the number of subdivisions , it is to be presumed that no difficulty will occur in the application of ...
Page 84
... out the transverse distance of the given degrees , and lay this on the arch , which will mark out the angular distance required . Case 2. When the given degrees are more than 60. 1. Open the sector , and describe the arch 84 MATHEMATICAL.
... out the transverse distance of the given degrees , and lay this on the arch , which will mark out the angular distance required . Case 2. When the given degrees are more than 60. 1. Open the sector , and describe the arch 84 MATHEMATICAL.
Page 85
... lay it off twice , if the degrees were halved , three times if the third was used as a transverse distance . Case 3. When the required angle is less than 6 degrees ; suppose 3. 1. Open the sector to the given radius , and describe the ...
... lay it off twice , if the degrees were halved , three times if the third was used as a transverse distance . Case 3. When the required angle is less than 6 degrees ; suppose 3. 1. Open the sector to the given radius , and describe the ...
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Common terms and phrases
acres altitude Answer arch azimuth base bearing blank line centre chains and links chord circle circumferentor Co-sec Co-tang column compasses contained decimal difference distance line divided divisions draw east Ecliptic edge feet field-book figures fore four-pole chains geom given number half the sum Horizon glass hypothenuse inches instrument Lat Dep Lat latitude length logarithm measure meridian distance multiplied natural co-sine natural sine needle Nonius number of degrees object observed off-sets opposite parallel parallelogram pegs perches perpendicular plane pole pole star Portmarnock PROB protractor Quadrant quotient radius right angles right line scale of equal SCHOLIUM screw Secant sect Sextant side sights square station stationary distance subtract Sun's survey taken Tang tangent theo theodolite trapezium triangle ABC trigonometry two-pole chains vane versed sine vulgar fraction whence
Popular passages
Page 38 - The angle in a semicircle is a right angle ; the angle in a segment greater than a semicircle is less than a right angle ; and the angle in a segment less than a semicircle is greater than a right angle.
Page 25 - The circumference of every circle is supposed to be divided into 360 equal parts, called degrees ; and each degree into 60 equal parts, called minutes ; and each minute into 60 equal parts, called seconds ; and these into thirds, &c.
Page 197 - RULE. From half the sum of the three sides subtract each side severally.
Page 106 - C' (89) (90) (91) (92) (93) 112. In any plane triangle, the sum of any two sides is to their difference as the tangent of half the sum of the opposite angles is to the tangent of half their difference.
Page 27 - The VERSED SINE of an arc is that part of the diameter which is between the sine and the arc. Thus BA is the versed sine of the arc AG.