It was followed by the metallic or flaming arcs. with long burning electrodes, the light radiation from which was due to the flame, in which substance entered the arc flame giving selective radiation. Such constituents as would help the efficiency were introduced as constituents of the electrodes.

From the present outlook it does not seem that any great improvements are likely in the existing types of arc lamps. If they are made, it would seem that "selective radiation" reducing the invisible heat rays and increasing the light emission relatively must be the keynote.

At present, light production is incidental to heat production and radiation. The reverse should be the case. A small heat production, or heat loss, should be incidental to the light production as the major effect.

Incandescent Lamps

The discovery that pure metallic tungsten had a melting point approaching that of vaporization of carbon, and the further discovery that with proper treatment the metal might be made ductile and be drawn into wire has had an inestimable effect on the growth and application of electric lighting. But the fundamental property on which the advantages attained rest is the low vapor tension of tungsten at very high temperatures of incandescence. Without this property the tungsten filament would not be of much advantage. It was this property which enabled the efficiency of light production to be nearly trebled at a stroke, with the result of the substantial disappearance of the carbon filament for lighting.

Scientific research applied to industry brought about this result, but it did not stop there. Langmuir, in recognizing the fact that in an inert gas instead of a vacuum the evaporation of the metal might be considerably lessened, while by coiling the filament into a small compass the removal of heat by convection of the gas might also be minimized gave us the halfwatt lamp, or gas-filled lamp, at the same time that a doubled output of light from a given energy was realized a color of light measurably approaching that of the carbon arc was also the result. White light has value in favoring acuity of vision by allowing contrasts of color to have their full effect, so that with it a lower illumination may suffice for visibility of objects of varied tints.

But we still strike the bass notes to get the overtones. Heat radiation from the filament, invisible and of no value in lighting, still constitutes by far the larger part of energy expended. The visible rays constitute not more than a small percentage of the radiation as valued in energy. If we estimate it as approximately ten per cent, we have left a large margin for future further development. Unless we can be assured of the existence of substances in nature which surpass tungsten in those properties in which it surpassed carbon as a filament, the way does not seem open to increase efficiency as obtained by further raising the temperature of the radiating body.

By the discovery, however, of substances which, when energy is delivered to them, confine in large measure their radiation to the visible spectrum as true light rays, the problem might be solved. Here the research laboratory will have its resources taxed as never before, for such refinements of results are always the most exacting and difficult. However, it may be confidently asserted that stability for a considerable period has been reached in present types of incandescent lamps, and no disturbing factor is at present to be anticipated.

Other Lamps

Just here it may be remarked that the established voltage for incandescent lighting, i. e., 110 volts, had its origin in the carbon filament lamp limitations, and the original central station distributions of D. C. current, which did not possess the flexibility of the A. C. system. On those original D. C. systems any lamp which was not adaptable to such a voltage as 110 was not capable of use. The difficulty of running arc lamps across the 110-volt supply is remembered by all operators.

With the alternating current system, however, the ratio of transformation can be adapted to peculiarities of the load apparatus. An inherently efficient lamp of even as low voltage as 20, more or less, may be operated with advantage by transformers.

In this connection there may be mentioned a late development involving the production of an arc between separated small masses of tungsten as the arc electrodes, which promises, at least for fairly large units, an increased efficiency of light production and one surpassing that of other light sources in use. The exact limit which may be reached will vary with the size of the unit, but will be double at least that of the best results with any incandescent type. The tungsten arc, being enclosed in a sealed bulb, combines ease of application with long life. As an approximate point source where the beam is to be "manipulated" optically, so to speak, it is peculiarly well fitted. Hence, for reflectors and lantern service, it is likely to be used, while its high intrinsic brilliancy may allow it to replace ordinary arc lamps in the lighting of large spaces.

The mercury vapor arc lamp is an example of a light source in which the emission is highly selective, but, unfortunately, the red rays are absent from the emission. On the other hand, the radiation from rarefied neon carrying a discharge is likewise highly selective in the red. These two sources worked together in proper relation may supplement and correct each other, but no simple lamps embodying the principle exist.

So long as there is in the production of light for illumination such a large margin of waste energy in the form of heat to conserve, so long will there be need of careful research work in lamp improvement, just as in the production of power from fuel a similar large waste exists which must gradually be diminished by research in power production.

If the past history may be taken as a guide to the future, progress will consist in further perfecting

Electric Power

Motor power and heating are essentially important, not because of the mere power or the mere heat which they produce, but because of the byproducts in the way of improved service leading to new methods, new processes, accuracy of control and the like.

The new developments in improved operation are the most valuable features in machine tool drive, on the electric-driven ship, in the enameling oven, in electric welding and in the electric furnace. The electrical engineer and the electric power company cannot be confined by the terminals of the electric circuit, but must enter intimately into the ultimate appliances. Everybody's business is allied to the business of the electric company.

Electric companies have done much more than to supply power; they have directed its use and have shown how to get larger and better results by electric methods. Not only this, but they have put operating conditions under exact control. Power and energy are measurable, and by recording and watthour meters a new insight into many operations is afforded. In this and other ways new manufacturing and business and accounting methods have been brought about, extending the electric influence far beyond the motor belt.

The prime function of electric power is to increase many fold the results that a man can accomplish. The horsepower per worker is a measure of industrial efficiency, and America may be proud that her horsepower per worker is high.

But in general manufacturing the cost of power is only about two per cent of the total. It is but a small fraction of the labor cost. The prime effort should

Report of Committee on

W. C. L. EGLIN: Gentlemen, our report is very short. There is only one suggested change in the Constitution on the recommendation of your Executive Committee, and your Committee submits the following recommendation:

That Section 7 of Article IX, Geographic Division of the National Constitution, now reading:

"The National Executive Committee, after consideration and approval of the detailed budget submitted by the Geographic Division, shall authorize the Treasurer of the Association to pay to the proper officer of the Geographic Division an amount which, in the judgment of the National Executive Committee, is necessary to finance the Geographic Division properly, but the amount in no case shall exceed 50 per cent of the yearly dues received from Class A and Class B members of such Geographic Division.

be to employ more power and less labor. The amount of power may be doubled or trebled if the workers' output can be raised even a few per cent. The probable coming scarcity of labor, the threatened competition in industry, the desire to maintain. a higher standard of living, the elimination of waste -all call for a larger and a more effective use of power in industry, on the farm, in the home.

The key to prosperity is greater production by machinery and power.

The Power Company and Engineering

This view of the present and the future indicates that the underlying conditions of progress rest upon progressive technical knowledge and engineering skill. A fractional increase in economy or the laying out of a great system requires engineering ability of increasingly higher order as the problems become more exacting and the consequences of failure more disastrous.

The power industry includes many companies; they must co-operate; the fine beginnings of coordinated effort in the activities of the Technical National Section during the past year, both within. the Association and in conjunction with other interests, give promise that future problems will be solved, for to the engineer a problem is an opportunity.

Engineering development and progress is fundamental to electrical power development. This fact is the keynote of this report. The Committee has accomplished its purpose if executives of power companies more clearly realize that successful financial and commercial expansion must be based upon sound and progressive engineering.

THE PRESIDENT: The next business is the Report of the Committee on Constitution and By-Laws, which will be presented by Mr. W. C. L. Eglin, Chairman, of The Philadelphia Electric Company.

Constitution and By-Laws

"The expenditures of a Geographic Division in so far as the responsibility of the National Electric Light Association is concerned, must not exceed appropriations authorized by the National Executive Committee."

be modified to read:

"The National Executive Committee, after consideration and approval of the detailed budget submitted by the Geographic Division, shall authorize the Treasurer of the Association to pay to the proper officer of the Geographic Division an amount which, in the judgment of the National Executive Committee, is necessary to finance the Geographic Division properly, but the amount in no case shall exceed 50 per cent of the yearly dues received from Classes A, B, E, F, G, members of such Geographic Division.

"The expenditures of a Geographic Division,

Committee

stand that none of the essential features necessary to make a standard aand interchangeable plug are covered by patents so that the adoption of this type as a standard will not lead to a monopoly.

Under these circumstances we see no reason why our member companies should not make every effort to see that such appliances and devices as they purchase and exhibit in their show rooms, which require an attachment plug, be fitted with standard plugs, and that they recommend that such receptacles as are installed under their direction or in the premises of their customers should have slots arranged to take the caps of the standard plugs.

In order that in the future plugs, caps and receptacles should continue to be interchangeable it is desirable that the questions of the exact dimensions and limits of tolerance of the various parts should be considered, determined and possibly reproduced in steel gauges, which could be used as a test to see that the output of new manufacturers as they come into the field is also interchangeable and to see that slight changes of dimensions should not creep into the work and factories of the present manufacturers.

We have recommended to the Associated Manufacturers of Electric Supplies that they should take up this work in conjunction with the American. Engineering Standards Committee.

Fig. 1-Attachment Plug

Fig. 2 Standard Receptacle

Section II

3-Wire

Section IV

Plug Connections for Brackets and Ceiling Fixtures

This subject was referred to in our last year's report and has been very active during the year. The manufacturers recognize the desirability of this development and the importance that when it comes the various plugs and receptacles shall all be interchangeable, and also the importance that the receptacles shall be so fitted that they can take the ordinary attachment plugs.

Several forms have been suggested and while all the manufacturers have not as yet agreed on a standard interchangeable design, yet we feel sure that they are making progress in this direction. Section V

Sample Boards of Wiring

The Committee has felt it desirable to be able to place before the members actual examples of the different kinds of wiring that are in use in this country and also elsewhere.

With this in view, the Commonwealth Edison Company very kindly cooperated and has donated to the Association a beautiful oak board designed with numerous panels, on which panels are shown various types of wiring, such as open wiring, wood moulding, metal moulding, wire mould, etc.

nother panels are shown the ordinary conthe wiring with knobs and tubes, both with and to the loom protection for the concealed but These panels, as are the others, are recere so that an inspection of the board shows anhe wiring looks both on the surface and besithe partition.

32

At last year's convention we reported that the tests of heater cords were not yet complete. They were completed and published complete in the November Bulletin of the N.E.L.A. and showed that among standard No. 16 heater cords on the market, all approved by the underwriters and designed for use with domestic flat-irons, there were very great differences in the durability, both under bending and abrasion.

These tests were published by the committee without any clue to the manufacturers' names, and the idea of the committee is not to put any pressure on any particular manufacturer, nor to approve or disapprove of any goods by brand or name; but the idea of the committee is to make available to the purchasers, standards with which they can compare the cords which they are purchasing for future use, and we believe this is the best and wisest method to incite an improvement in the quality of cords.

The policy of the committee is not to spend any more money than is necessary to start the work of testing.

The theory of the committee is that once the attention of the members and users of heater cords and other cords has been called to the importance chasing only cords which show up well, that after of having these tested for durability, and of purthis has been done, the manufacturers will have their cords tested from time to time so as to furnish information of what qualities are available.

The committee, therefore, this year, has made only a few tests of some lamp cords and of some No. 18 heater cords vs. No. 16. Last year all our tests were on No. 16.

The tests on the No. 18 cord compared with No. 16 of same brand and year indicated that the No. 18 would probably stand up much better than natural thing to expect, since, of course, a small the No. 16 cord under bending, which is a very cord should bend more easily than a large one.

In comparing the No. 16 cord tested this year with the No. 16 cord of the same manufacturer as tested last year, the fact was apparently developed that this year's No. 16 cord of that particular manufacturer was of distinctly lower quality as respects durability than the cord which he had submitted last year for the first tests of the committee. In accordance with the directions of the committee, the Laboratories do not communicate to