Oct. 1926 ILLUMINATION I T E M S 1039

by prismatic refraction with comparatively little loss. In fact, the inside frost allows an even greater portion of the light to pass through than does a similar frost on the outside of the lamp. This is due to the fact tha t the multiple internal reflections are not so numerous in the inside frosted lamp because the rough, interior surface does not reflect any considerable portion of the light back and forth inside the lamp, as happens with the outside-frosted lamp. Moreover, the relative absorption of the inside frost does not increase so rapidly with the life of the lamp as does that of other diffusing media.

For these reasons, then, the inside-frosted lamp is only about two per cent less efficient than a clear lamp, contrasted with a loss of efficiency of three to four times this much in the old style sand-frosted and sprayed lamps.

Another great benefit of the discoveiy of inside frosting is a t once apparent when it is realized that now the manufacturers need only one type of lamp of each wattage instead of lamps with several different finishes. This is beneficial not only from the standpoint of economies resulting from the increased use of auto­matic machinery and the decreased investment in lamps lying idle in warehouses and on dealers' shelves, but also there 13 still greater benefit for the public in general. Since the inside-frosted lamps give practically as much light as clear lamps, they can be used to replace clear lamps for every ordinary use. This means that wherever, because of ignorance or carelessness, lamps are used without proper shades or glassware, the inside-frosted lamps will afford a certain degree of eyesight protection. Furthermore, wherever lamps are properly shaded, the inside frosting will eliminate sharp shadows and striations, with negligible loss of efficiency.

The invention of the inside-frosting process, of the same order of importance as the invention of gas-filled lamps and tipless lamp construction, is one more example of the value of systematic research, persistently pursued.

EUROPE ORGANIZES I T S L I G H T I N G ACTIVITIES Within the last two or three years an increasingly

greater amount of attention has been given in various European countries to the promotion of better lighting in factories, homes offices and the like. Lighting demonstrations, illumination courses, technical and advertising literature are all being pressed into service to carry the message of good lighting to the people of many foreign lands. A list of some of the European countries where this work is now being carried on intensively would include England, France, Germany, Italy, Austria, Sweden, Czechoslovakia, Belgium, Scotland and perhaps some others.

Holland has only recently organized an Illuminating Engineering Society which is supported by a number of able and prominent men.

Like some of the others, this new society has the following objects :

1. To educate the public in the art of illumination by

lectures, demonstrations, publications and the like. 2. To demonstrate proper and practical ideas about

lighting to pupils already in school. 3. To encourage the application of proper lighting

in practise by giving information and advice to those who desire it.

4. To bring about new applications and improve­ments in lighting through the standardization of accessories and development work.

I t is being organized to accomplish these things by means of permanent demonstration rooms, illuminating engineering and general educational service.

A lecture given by Mr. C. P . Jensen before the thirty-first Congress of the V. D. E. (Association of German Electrical Engineers) in June, at Wiesbaden dealt with the German Society of Lighting Economics from the point of view of the electrical organizations in Germany. I t was a plea to them to unite in a coopera­tive movement for a broader understanding of lighting economics as a means of rendering a greater service to the users of light.

Once a suitable neutral basis for the cooperation of the electrotechnical industry has been created in the field of illuminating economics, there remains only the question of its practical influence on the broad masses of the light-consuming public with the view to in­creasing the service of this great electric lighting industry.

I t is hoped that a growing demand for electric lighting service will be established and that through increased production and other advantages to be derived from better lighting, a great economic good will be accomplished.

Europe today, says Mr. Jensen, is setting out on a program of electrical standardization similiar to that which has meant so much to electrical progress in America. Plans are being made to standardize the voltages of lighting circuits and to decrease the number of lamp types.

These German activities received their impetus over a year ago with the opening at Berlin of the new "house of light" containing a group of lighting demonstration rooms. Since then some 50,000 people have been initiated there into the "mysteries" of good lighting. Furthermore, many well attended illumination courses have been given and these have helped to spread the idea of the advantages of better lighting.

T R E N D OF ELECTRIC L I G H T I N G Significant are many of the trends shown in the

annual report of the National Electric Light Associa­tion's Lamp Cηmmittee. In three years the average wattage of lamps consumed has risen from 55.6 to 57.6; the percentage of exactly 115-volt lamps has risen from 42.8 to 44.6. T h e Committee recommends tha t every member company have a "well organized Lighting Service Department," and that there be permanent lighting demonstration rooms in every city of the country.