The Golden State: Where & How to Live, Secure, Visit, Enjoy and Thrive in California

Turning Night Into Day

Light costs us a tremendous amount not only because our lamps are poor but also because our present power-stations are very poorly constructed. In the steam boiler, in the steam-driven machinery, in the dynamos and in the wiring which carries the electric current a tremendous amount of precious energy is lost. A lamp gets only one fifth part of the energy which is generated in the fuel. And of this fifth only a hundredth part is actually delivered as light. That is, when we spend 500 dollars for coal we get only one dollar's worth of light.

The Best Lamp in the World

There is one lamp which gives off only light rays without any heat rays at all. I am sure you have seen this best-lamp-in-the-world many times in the grass on summer nights. It is the lantern of the glow-worm or firefly.

Isn't it amazing that the little glow-worm gives a light that is not only better than our best lamps but even better than the sun itself! The sun gives off five times more heat than light rays, but the glow-worm gives off only light rays. Its light is cold. If it were hot, it would burn itself up.

And the glow-worm outdoes the sun in another respect too. Its light is far superior to sunlight. Sunlight, or the light of an electric lamp, seems to us to be a white light. But it is really made up of a mixture of different rays: violet, indigo, blue, green, yellow, orange and red.

Sometimes a sun ray is separated into its different light rays, refracted. You have all seen how it is refracted when it goes through a prism or the edge of a mirror, throwing a multicolored bar of light on the wall. And the rainbow is also a ray of sunlight which has been broken up into its parts, refracted.

Now all rays are not equally good for the vision. Red light tires the eyes and seems dim to us. That is why no one works by a red light. The eye is much more sensitive to a green light. That is why shades on workers' lamps are usually made of green.

In incandescence we always get a lot of red rays. When we heated up our poker it first gave off a red light, one by one the other colors were added to it until it finally got white; that is, a mixture of all the colors.

The higher the temperature, the fewer there will be of the unpleasant dim red rays in comparison with the others. Therefore, to make a brighter and more agreeable light, inventors tried to raise the filament in the electric lamp or the Welsbach mantle in the gas lamp to as high a temperature as possible.