The Caldwell Tribune

DAYLIGHT AHEAD.

Latest Stage in the Evolution of the Electric Light.

Fireflies are still in advance of mankind in the matter of economical light producing.

The phosphorescent glow which they give off is nearly pure light, says the Independent.

Very little of the energy is wasted in heat, while in the case of the lighting devised by man more power is used up in producing heat, which is usually not wanted, than is converted into visible light.

The nearest we have yet come to following the fireflies is the mercury vapor light developed by American inventors, which, in the form of long, glowing tubes, has been seen in our shop windows as advertisements for two years or more.

They produce more light at less cost than any other practical method of illumination and would be extensively used if it were not for the color of the light. It contains no red rays, but is strongest in the violet end of the spectrum, extending far beyond the limits of visibility in that direction and including an abundance of rays that we can photograph, but cannot see.

This mercury glow light has made the "while you wait photography" of the pleasure parks a possibility, but it is too ghastly for common use. It would turn a parlor into a morgue or a sauce room.

But recently it is reported that German chemists have overcome this difficulty by putting into the electrodes other metals besides mercury, thus changing the character of the light and making it approach the light of common day.

Zinc with 10 per cent of bismuth and a trace of sodium is used for this purpose.

If this proves practical we shall have our houses cheaply lighted by softly glowing tubes arranged in all sorts of artistic designs on the walls and ceilings instead of one or more points of light too bright to look at directly.