ELECTRICAL RAT EXTERMINATOR
Rats are given a day or two to grow comfortable first.
The box is placed with its top cover open, which disconnects all current, while rats enter and leave freely to grow accustomed to it. Oil in a pivoted container emits an odor through apertures in the side walls, drawing rats through openings near the base. The rat climbs an asbestos-covered inclined grid toward the oil, using lower steel wires for footing, and steps onto upper copper wires charged with high-voltage current. The circuit completes and the rat is electrocuted on the grid.
“The said device having a top hinged thereto, which is left open for a day or two permitting the rats to freely enter and leave my improved device so as to become accustomed to and not afraid of same.”— John Kaiser, from the specification
And the world did not beat a path to his door.