| 摘要 |
The instrument includes a rectangular support with its opposite edges (41,42) provided with symmetrical graduations relative to the support longitudinal axis. Similar graduations are provided on the other two sides of the support. The lower side of the support is placed on the latitude of the point to be located on the map. A line is then drawn along the normal side of the support (43). The operation is repeated for the longitude of the point. The intersection of the two lines determines the position of the point.
|
