A practical treatise on the science of land and engineering surveying, leveling, estimating quantities, &c

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1885 Excerpt: ...reach to 47 14' the z B C D, the complement of which is 42 46 the z B. To find the angle B. Extend the compasses from 4960 AC to 1911, the less segment; that extent from radius on the sines will reach to 22 39' z AC D, the complement of which is 67 21' the z A: the supplement of the sum of the angles A and B equal to 69 53', the angle A C B. By Logarithms. As 6880: 11716:: 1796:: 3058 diff. of segments Half diff. of segments 1529 Half the base 3440 + £ the diff. 1529 = 4969 greater segment Half the base 3440-the diff. 1529 = 1911 lesser segment To find the z A. As the side AC 4960.. 3.695482: radius 10.000000:: the side AD 1911.. 3.281261 13.281261: the co-sine A 67 21' = 9.585779 To find the z B. As the side B C 6756 3.829690: radius 10.000000:: the side BD 4960 3.695482 13.695482: the co-sine B 42 46.... =9.865792 The supplement of the angles A and B equal to 69 53' =. C Problem 70. Example for Practice. In the triangle ABC; given the side A B 930, the side AC 600, and the side CD 650; required the angles. First, by geometrical construction. Second, by Gunter's scale. Third, by logarithmic calculation. Problem 71. Miscellaneous Questions for Practice. Fig. 10, Plate 27. It is proposed to throw a bridge across the river; what is the exact distance from C to D? Given the line A B 1017, the Z A 41 29', the Z B 35 01', to find the line C D. To find the C. B 35 01' + A 41 29' = 76 30'-180 00-= 103 W C To find the side A C. To find the side B C. As sup. sin. C 76 30'. 9.987832 As sup. sin. C 76 30'. 9.987832: side A B 1017.... 3.007321:side A B 1017.... 3.007321:: sin. B 35 01'... 9.758772:: sin. A 41 29'... 9.821122: side A C 600. = 2.778261:side B C 692. = 2.840601 Then by Case 3: As 1017: 1292:: 92: 116.877 diff. of segments 58.438 half diff. Half the b...