thumbstall

Captains of guns to provide themselves with percussion-primers, thumbstalls, and priming-wire, and to see that the men of their respective parts of the gun's crew discharge their several duties promptly and carefully.

"I thank ye," she said heartily, and pressing down the thumbstall of the latch, went in.

The thumbstall has been made of various materials, but its use is somewhat inconvenient for the Gun Captain, and he cannot feel that the vent is stopped.