. Railroad construction. Theory and practice. A textbook for the use of students in colleges and technical schools . ifficult work, where there are ob-structions, a valuable check on the accuracy may be found bysighting backward at any visible station and noting whether Fig. 11. 26 KAILROAD CONSTRUCTION. §26. its deflection agrees with that originally computed. As anumerical illustration, assume a 4° curve, with 28° curvature,with stations 0, 2, 4, and 7 occupied. After setting stations1 and 2, set up the transit at sta. 2 and backsight to sta. 0with the deflection for sta. 0, which is 0°. The
. Railroad construction. Theory and practice. A textbook for the use of students in colleges and technical schools . ifficult work, where there are ob-structions, a valuable check on the accuracy may be found bysighting backward at any visible station and noting whether Fig. 11. 26 KAILROAD CONSTRUCTION. §26. its deflection agrees with that originally computed. As anumerical illustration, assume a 4° curve, with 28° curvature,with stations 0, 2, 4, and 7 occupied. After setting stations1 and 2, set up the transit at sta. 2 and backsight to sta. 0with the deflection for sta. 0, which is 0°. The reading on is 2°; when the reading is 4° the telescope is tangent tothe curve, and when sighting at 3 and 4 the deflections will be6° and 8°. Occupy 4; sight to 2 with a reading of 4°. Whenthe reading is 8° the telescope is tangent to the curve and, byplunging the telescope, 5, 6, and 7 may be located with theoriginally computed deflections of 10°, 12°, and 14°. When oc-cupying 7 a backsight may be taken to any visible station withthe plates reading the deflection for that station; then when.
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishernewyo, bookyear1913
