A movable piece of ivory, lead, or other material, connected with the bellows of an organ, that gives notice, by its position, when the wind is exhausted.
A machine or contrivance for indicating or recording something, particularly for keeping a check upon employees, as factory hands, watchmen, drivers, check takers, and the like, by revealing to their employers what they have done or omitted.
Any distinguishing mark, projection, groove, etc. on a pattern, core box, mold or core which acts as a guide mark for assembling matching parts. See Core, Core Box, Mold.
An arrangement consisting of long strips, as of rope, wire, or leather, hanging from a bar over railroad tracks, in such a position as to warn freight brakemen of their approach to a low overhead bridge.
A curtain-like signal consisting of lengths of chain or free-swinging rods suspended over the tracks to warn workers on the top of moving cars of an approaching low clearance such as a bridge or a tunnel entrance.
A strain indicator, usually comprised of a sleeved free-standing rod cast in place in a drilled pier or pile to measure relative movement between the anchored (embedded) tips of two or more rods or between the rod anchor and the top of the pier or pile.
A small line free to flow in the direction of the breeze. It is attached to sails, stays in the slot and in other areas, enabling the helmsman and crew to see how the wind is flowing. Proper use of the telltales can help sailors improve their sail trim.