dumpy level

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A surveyor's instrument having a short telescope fixed rigidly to a horizontally rotating table.

GNU Webster's 1913

1. (Surv.) A level having a short telescope (hence its name) rigidly fixed to a table capable only of rotatory movement in a horizontal plane. The telescope is usually an inverting one. It is sometimes called the Troughton level, from the name of the inventor, and a variety improved by one Gavatt is known as the Gavatt level.

WordNet 3.0

1. n. a surveyor's level having a short telescope fixed to a horizontally rotating table and a spirit level