plumb bob

And at last he was dangling at the end of the rope like a plumb-bob.

He thought that a plumb bob dropped through the long axis of the rocket would form a right angle with the surface of Arzachel.

With a tape line, gimlet, and plumb-bob, a mechanic is fully equipped with tools to get his measurements.

A plumb bob must be attached exactly in the center of the tripod head.

Our surveying apparatus was a triangle and a plumb bob which we made ourselves.