TRAP
A snap trap narrow enough to insert into the gopher's hole.
The trap is set by lifting the jaw lever against coil spring tension until a curved arm catches on a stop projecting from a spring-loaded treadle. The whole assembly is inserted into a gopher hole. The gopher passes between the open jaws and steps onto the wider portion of the treadle; its weight depresses the treadle and clears the stop from the arm. The coil spring snaps the toothed jaw down onto the fixed cross-bar jaw with the gopher between them. A chain at the base end allows the trap to be pulled back out of the hole.
“When the gopher passes between the jaws and reaches over the wider portion of the treadle 23 the leverage of its weight pushes the treadle 23 down toward the base 6 thereby moving the stop 26 out of the way of the curved arm 18, whereupon the coil spring 21 through the arm 18, snaps the lever 12 and the transverse jaw 16 upon jaw 7 and upon the body of the gopher therebetween.”— Durward B. Hampton, from the specification
And the world did not beat a path to his door.