The following is a description of a device I built at my home in Brooklyn, which not only gave us relief from the nightly feline concerts, but also furnished much amusement to my friends.
Illustration: Electric Apparatus for Driving Away Cats
I first ran two bare copper wires along the top of the fence about 1 in. apart, fastening down with small staples, care being taken that they did not touch. To the ends of these wires I fastened ordinary insulated bell wire, running them to the house and connecting them to the upper binding posts of an induction coil; I then ran a wire from the lower binding-post of my coil through the batteries back to the other lower binding-post of coil, breaking the circuit by putting in an ordinary switch. The more batteries used, the stronger the current. The switch should always be left open, as it uses up the current very rapidly.
When "tabby" is well on the wires I close the switch and she goes the length of the fence in bounds, often coming back to see what the trouble is, thus receiving another shock. --Contributed by Charles L. Pultz.