Hints to travellers, scientific and general (1901)
Royal Geographical Society (Great Britain) · London, The Royal Geographical Society · leaf 119
95 SEXTANT AND PRISMATIC COMPASS SURVEY. Any object whose true bearing is east or west must be in the same latitude as the place of the observer. Any object whose true bearing is north or south must be in the same longitude as the observer. 3. Special survey of a small tract of country, with… … AB --Mainline. ^ ^ ^ j- —Principal triangles. C c— 1 Tie line. measurement of a base. Having fixed upon a base, A B, set the compass up at A, and take a round of bearings to B and other selected stations, C, D, E, &c. ; then mark A on the field-sheet, in such a position as will enable the whole…
