A small packet of explosive material with wire appendages allowing it to be conveniently attached to a railroad track. It will explode with a loud report when run over by a train, and is used to provide a warning signal to the engineer.
The track of a buck.
The cone or conical wheel of a watch or clock, designed to equalize the power of the mainspring by having the chain from the barrel which contains the spring wind in a spiral groove on the surface of the cone in such a manner that the diameter of the cone at the point where the chain acts may correspond with the degree of tension of the spring.