Originally published in the Electrical Experimenter (issue unknown but probably late 1916).
This version from the Fort Wayne Journal-Gazette 24th Dec 1916 p12
It is probably more a ‘electric dog’ than a creature built to exhibit phototropic behaviour and the like. Although it has a selenium cell, it is for selector circuit activation purposes, not light following. I’ll refer to this dog again in the robots section, as the design principles are largely those used in all the early mechanical men, automatons, robots, etc.
The Wireless Dog That Will Follow You Around
And How to Make One Just Like It Yourself For a Christmas Present
He Can Growl, Scare Tramps, Follow You, Flash His Eyes, Come When Called, And He CAN’T BITE!
When you wake up on Christmas morning how would you like to find beneath your stocking an electric dog that will follow you around like a faithful pup, that will growl when you want bun to growl, and glare at intruders with flame-shot eyes?
Better still, how would you like to make such a dog yourself? For, if you want him, you will have to make him, which will not be difficult if you have a fair knowledge of electricity and of electrical apparatus.
The first thing to make ie the "works".
When these are all complete and in running order they should be encased in a hollow shell of papier mache on a wooden frame, or the frame may be covered with paper and shellac.
The mechanism of the dog is described in the Electrical Experimenter by F. A. Steinbrook. It is all based upon the fact that the mineral selenium, which is not normally a conductor, becomes a conducor of electricity as soon as a ray of light falls upon it. Therefore a selenium cell is placed where it will fit into the top of the dog’s back when the animal is completed, in such a position that light rays may be focussed upon it. As soon as this happens the selenium closes the circuit to the polarized relay (8) in the accompanying diagram.
This closes the circuit to the selective device (1), and the magnet (12), which releases the rotator and this will continue to revolve until the circuit is closed.
It can stop at any one of six positions called stops.
If the light be flashed and immediately shut off the rotator turns to stop 1. This closes a circuit and starts motor 5, and the dog runs forward.
A second flash sends the rotator to stop 2 and closes the circuit to the solenoid 9. This turns the wheel 21 to the
left, steering the dog in the same direction.
A third flash, and the rotator goes to stop 8, closing the circuit to solenoid 8 and making the dog turn to the right
A fourth flash, the rotator is at stop 4, closing a circuit to the electrical horn; which is adjusted to emit a growling note.
A fifth flash and the rotator moves to stop 6, closing a circuit to the automatic flasher (7), which makes the electric lights (19) -flash on and off behind the pup’s glass eyes.
To know certainly at what point the rotator stands, a pointer should extend up to the dog’s back and move upon a dial numbered from 1 to 6.
A small aerial may be mounted on Towser’s back, and when it is desired to control the nimal wirelessly the switch 4 is turned to. point 2. This places the coherer in circuit with the polarized relay (3). A copper plate (18) on the dog’s side serves as a capacity ground. Each time the key of the radio sending set is depressed, the apparatus will work in the same manner as when operated by flashes upon the selenium cell.
The animal may be simplified by making him obedient only to wireless, or exclusively to light. Now, here is an opportunity to make a really useful, not to say ornamental, Christmas present for somebody, and there is still time to do it before Christmas. There is no use trying to buy one of these wireless hounds, because they are not for sale. If you want one you will have to exert all your mechanical and inventive genius in constructing one according to the working diagram given herewith. The wireless hound has many advantages which common dogs do not possess—you don’t have to pay a dog license for him or buy him a muzzle and he won’t run away.
Captions:
HERE is a wiring diagram for the wireless dog showing relation of propelling motor, radio apparatus, selenium cell, steering mechanism, eye lamps, flasher and growl producer.
THIs sectional view shows how to build up the interior mechanism of the wireless dog.