A treatise on surveying ; in which the theory and practice are fully explained (1860)
Alsop, Samuel · Philadelphia, E. C. & J. Biddle & co. · leaf 207
the radius and one leg at E and W. A skeleton protractor is thus formed, having the North,South, East, and West points, as well as the 30° and 60°points, accurately laid down. Commencing with the first bearing, which in the figure is!N\ 27| E., divide it by 2, and from the table of naturalsines… … Sec. VI.] PLATTING THE SURVEY. 205 The second bearing is S. 60J° E. The half of J° is 15:the sine of this is 0.0436. Lay off .04 from 60° to 2. The third bearing is S. 8° E.: the sine of 4° is 0.6976. Layoff .70 from S. towards E.: the point 3 is thus determined. The fourth is S. 47^° E., which…
Surveying
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
