plane table

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A portable surveying instrument consisting essentially of a drawing board and a ruler mounted on a tripod and used to sight and map topographical details.

Century Dictionary and Cyclopedia

1. n. An important instrument of topographical surveying, consisting of a drawing-board mounted upon a tripod, and capable of being leveled and turned in azimuth, sometimes also having two horizontal motions of translation. An indispensable accompaniment of the plane-table is the alidade, which is a straight-edge carrying upon a standard a telescope with cross-wires (generally with a telemeter), which telescope is horizontally fixed relatively to the straight-edge, but has a motion in altitude. The alidade generally carries a delicate magnetic needle. A certain number of points having been geodetically determined and marked by signals, the plane-table is set up at any other point, and the paper upon which the map is to be drawn, having the trigonometric points laid down upon it, is placed upon the table. The latter is then brought into proper orientation, and the position of the station determined graphically by the three-point problem. The plane-table presents some slight difficulties when the scale is to be so large that the board itself appears of considerable size on the map, and especially when irregularly laid out towns are to be surveyed with the last degree of accuracy. On the other hand, the plane-table is of little use in mere reconnaissance. But in most cases it is the chief instrument of the topographer, and is used in all topographical surveys except those of Great Britain.
2. n. In mining, an inclined table or surface of boards on which ore is dressed; a frame, or framing-table. Also plain-table.
3. To survey with a plane-table.

Wiktionary

1. n. cartography A particular kind of instrument used by surveyors in mapmaking.

GNU Webster's 1913

1. adj. an instrument used for plotting the lines of a survey on paper in the field.
2. See under plane, a.

WordNet 3.0

1. n. surveying instrument consisting of a drawing board and a ruler that are mounted on a tripod; used to sight and map topographical details