A team at Disney Research recently developed some pretty amazing technology that lets you transmit sound through your fingertips. Some clever inventors way back in the 1920s had a similar (if decidedly more primitive) parlor trick. They called it the Talking Glove.
All you needed to make this magic glove contraption was a few batteries, some wires, two metal rods, an induction coil, a leather glove (naturally) and a microphone or phonograph.
The February 1923 issue of Practical Electrics magazine included a cover with this "talking glove" and even included instructions for how to build it. I've included a transcribed version of the article below. If you decide to build your own, please send me a video! I'm curious to see how well this would work with a few modern day tweaks.
This is an experiment which the writer performed some years ago, and is now brought back to life with some little variation. It is an interesting demonstration that can be produced by any one, and the appliances necessary are simple.
We first need a good microphone, which, however, can be home-made. Some one of t h e microphones described in the columns of this journal can be employed with good results. We also require a primary battery (A), which may consist of either a few dry cells or a 4 to 6-volt storage battery. Next we have a spark or induction coil (SC). This coil may be a spark coil set as is used on a Ford car, or otherwise a good telephone induction coil, without any vibrator. If a spark coil with a vibrator is used, it is necessary that the adjusting screw be screwed tightly against the spring, so that it will not move.
Next we have a high tension battery (B) which is the usual radio "B" battery, and may be bought at any radio store. A voltage of 24 will answer, as a rule. If good results are not obtained with 24 volts, another 24-volt battery may be added in series. It is advisable to get a "B" battery with connections brought out, so that voltage can be varied. In this experiment the voltage required is often quite important, and a variation of a few volts will make a great difference. We also require metallic handles, such a s used on electric shocking apparatus (H and H1). A metallic screw driver or even a piece of wood, covered with tinfoil, to which a flexible wire is connected will do very nicely.
If all the connections are made, an assistant now speaks into the microphone (M). While one person holds in one hand one metallic handle, the other hand, covered by a kid glove, is held against the ear of a second person, who holds the other terminal in one hand. The glove will then talk distinctly and quite loudly. It is quite necessary that the glove in question be a kid leather glove. A cot- ton glove, or one of the soft leather variety, known as buckskin or chamois, will not work. The thinner the leather of the glove, the better the results. Note particularly that the glove must be perfectly dry. If it is moist or wet, a poor result will follow. Drying the glove over a stove or radiator before using it will improve the quality of the rendition.
There is a little trick in connection with this that is important. When holding the glove against the ear of the listening per- son, place the palm of the hand near the wrist against the cheek bone. This will bring the palm of the gloved hand over the ear. Do not touch that part to the ear of the second person. The idea is that the stretched glove over the palm will vibrate and the vibrations should not be impaired. You can easily demonstrate this to your own satisfaction by pressing the glove tightly to the ear of the listener. He or she will hardly be able to hear anything. But the instant the glove is removed, slightly, from the ear, the results will become astonishing. Always remember that the wrist of the gloved hand must actually make contact with the cheek bone of the face of the listener. If no contact is established, the device does not operate, for the following reasons:
The Talking Glove is a variety of talking condenser. By studying t e circuit it will be noted that the current from the high tension battery flows first through the secondary of the coil, then through the body of the operator, thence to the glove. The hand inside the glove is one plate of the condenser—the glove is the dielectric — the face, or cheek bone, of the listener is the other plate. The return circuit is completed through the listener's body into the "B" battery. It will be observed that the condenser is kept charged continuously through the high tension "B" battery, whether an operator speaks into the microphone (M) or not. Note also that the polarity of the "B" battery is important. It will work much better if the connections are made in one way than in another. The correct connection has to be found by actual experiment.
In our cover design we have shown how phonograph music can be transmitted through the Talking Glove. In this case a microphone button is attached to the tone arm of the phonograph, and the phonograph can then be closed so that little music issues from it. Or the phonograph may be in another room where the experiment is made. This will mystify the listeners still more. A microphone for phonographs has been described by the writer on page 354 of the July 1922, issue of Practical Electrics.
A good stiff piece of writing paper will do equally well. In this case the writing paper is placed over the ear, while the operator cups his hand on top of the paper. After a few trials, in order to get the necessary tension and pressure, it will speak loudly and distinctly.
The experiment of the Talking Glove can be varied somewhat by using two operators, each with a glove in his hand. Each should take hold of the metallic handles. Then if the two operators place their two gloved hands over both ears of the listener the sounds will be plainly heard.
For parlor tricks or amusement purposes, another variation can be made by having the two operators step, each with one foot, upon a contact plate, the bottom of the shoe soles being pierced by nails, while the inside of the shoes is covered with tinfoil or other metallic plate. It is necessary that no socks be worn, or holes may be cut in them for the foot to connect with the plates. In this case there will then be no visible wire or connection to the two operators, to the mystification of the listener. The gloves may be handed about for examination and put on or taken off right in the presence of the audience.
Images: scanned from the February 1923 issue of Practical Electrics