Which one of the following methods is not used for the reduction of a cadastral map ?

Question

Accepted Answer

The correct answer is Option 4: Dot Planimeter. Here's why:

*   **Why Dot Planimeter is NOT used for reduction:** A dot planimeter is an instrument used to measure the area of a figure on a map or plan. It doesn't directly facilitate the *reduction* (scaling down) of a cadastral map. While the area measured by a dot planimeter *could* be used in calculations related to scaling, the planimeter itself doesn't perform the reduction process. It's a measurement tool, not a reduction method.

*   **Why the other options ARE used for reduction (and therefore incorrect):**

*   **Square Method:** The square method involves overlaying a grid of squares on the original map and then creating a smaller grid with proportionally smaller squares on the new map. The features within each square on the original map are then transferred to the corresponding smaller square on the reduced map. This is a valid method for map reduction.

*   **Similar Triangle Method:** This method uses the principles of similar triangles to proportionally reduce the dimensions of features on the map. By establishing corresponding points and creating similar triangles, the map can be accurately scaled down.

*   **Camera Lucida Method:** A camera lucida is an optical device that allows an artist to see a superimposition of the subject being drawn and the drawing surface. In the context of map reduction, it allows a cartographer to trace features from the original map onto a smaller surface, effectively reducing the map's scale.

Therefore, because the dot planimeter is a tool for measuring area and not for reducing the size of a map, Option 4 is the correct answer. The other options are all valid methods for map reduction.