gunlock

Inside it was a clock, which could be set to run a certain time and then loosen a sort of gunlock.

Shorty turned around and backed up to him so that the calves of their legs touched, and began intently studying his gunlock.

He arranged a system of signals with Shorty, by which one click of his gunlock meant halt, and two to come ahead.

Si clicked his gunlock, and waited till he had counted 25 rebels gathered there, which seemed to be all, as no more appeared.

A small gunlock was armed with an excellent flint, and, on being snapped in an exhausted receiver, did not produce any light.