Page:Popular Science Monthly Volume 91.djvu/168

 152

The Effect of Electricity and Music on the Human Organism

THE effect of music upon the human organism, whether calming, exciting or otherwise, can be reproduced in a re- markable manner by means of electric currents. Dr. M. Dupont is responsible for much of the successful research in this direction and has obtained results that are not only interesting but of probable educational and medicinal value. Music consists of sound vibrations at certain regu- lar intervals. For a high note the vibrations are very rapid, while for a low note they are slower. To produce musical effects by electricity the alternating current is em- ployed, made up of periods, the frequency of which corresponds with the number of vibrations of the sound; that is to say, with the pitch. Upon passing the alternat- ing current through the body in the form of a mild shock an effect is produced similar to the physical thrill of appreciation for a musical performance. — H. J. Gray.

��Popular Science Monthly

��To Prevent the Ears from Perspiring When Using Telephones

NO doubt the wireless operator has often had the annoying experience of per- spiring ears. This inconvenience can be easily overcome in the following manner: Take a small piece of paper slightly larger than the receiver and place it between the receiver and the ear. I have found this to stop all perspiration without im- pairing the hearing.— W. T. Derr.

��A Rain Alarm Made of a Broken Electric Globe

HOW often the rain pours into a window at night and we know nothing of it until we awake and find the floor and carpet damaged! This can be avoided by installing a simple rain alarm which will ring an

���The electric lamp socket on a wood base and the connections with the binding posts

electric bell. To construct such an alarm proceed as follows: Remove the upper part of a carbon filament lamp by winding

��a piece of cotton string around the lamp just above where the platinum wires come through the stem. Saturate the string with kerosene, applying a lighted match, and, while the glass is hot, dip it into water.

��Dilute H 2 S0 4

����Bell

��battery

��Switch

���^W^T

��Wiring diagram showing the alarm gage in- stalled in a battery circuit for ringing bell

Screw the lamp into a porcelain receptacle mounted on a board. Make connections with a bell and two dry cells, as shown. Then place the lamp outside the window and fill almost to the platinum tips with dilute sulphuric acid. When a few drops of rain fall into the lamp, the solution, which is a good conductor, will cover the platinum tips and form a circuit, and thus ring the bell. The switch should be put near the bed where it can be turned on and off conveniently. — Wm. Warthen.

��Mounting Tinfoil on Glass Con- denser Plates

A GOOD shellac for fastening the foil to the glass in transmitting condensers may be made by dissolving as much pow- dered rosin as possible in I oz. of turpentine and thinning the mixture by the addition of ^2 oz. of alcohol. Only a very small amount of rosin will be needed.

About three drops of shellac should be put in the center of the surface of the glass and rubbed around well. Place the foil on the glass and roll it fast with a photo- graphic print roller. The foil must be placed on at once as the mixture dries quickly. When this varnish is used the plates may either be stacked or made into an open rack condenser. If plain turpen- tine is used the foil will not stick so well and consequently the plates must always be stacked. — Samuel W. Huff.

�� �