Root's Military Topography and Sketching

accurate adjustment alidade altitude azimuth bearing bisect bubble bubble-tube chain circle clamp clinometer coincidence COMMON LOGARITHMS compass constructed contour contour interval contour line correct cross-wires declination arc determined direction distance divided divisions draw drawn edge eleva equal feet FIGURE foot graduated ground height hence horizontal equivalents hour hour angle inch represents instrument intercepted intersection latitude length limb line of collimation line of sight located marked mean meridian line method mile minutes move needle north end object observation obtained offsets oriented paces paper parallel perpendicular plane table plate plotted plumb-bob plumb-line polar axis position prism protractor refraction revolved road ruler sextant side sketch slope solar solar telescope square stadia stakes station straight line strides subtract surface survey tangent screw telescope tion topographic transit transit telescope triangle true meridian turn unit of measure vernier vernier scale wire yards zero