TRAP
A spring-loaded lasso that ropes the animal by one leg.
A chain noose is arranged around a hinged pan, with a coiled spring arm held cocked by a catch on the pan. The animal steps on the pan; the pan swings downward and releases the arm. The arm snaps through a semicircular arc, drawing the noose taut around the animal's leg. A figure-8 terminal link engages the chain so the noose cannot loosen, leaving the animal tethered to a stake.
“The trap it will be perceived secures the animal, not by means of spring-backed jaws, but by means of a noose; it does not crush nor mutilate; it secures the animal painlessly; nor will the animal escape, leaving in the trap a severed leg.”— Vernon Bailey, from the specification
And the world did not beat a path to his door.