residence; 25 watts is big enough. If you figure on standardizing on a 50-watt mazda you will have a lamp which should only be used in about three places in the ordinary residence. I would suggest that the incoming Lamp Committee, if possible, get some figures as to the percentage of lamps of the size used in residences as against the size used in commercial places.

MR. J. W. CoWLES, Boston: Among the many valuable points of information brought out in the report of the Lamp Committee, I would like to emphasize one which it seems to me is particularly pertinent to the member companies at this time. I refer to the change from the basis of candlepower to lumens in the rating of incandescent lamps. The old basis of horizontal candlepower rating has had the one advantage of convenience. but beyond this little can be said in its favor, and it is perhaps fortunate if recent new developments in lamp manufacture are going to force the rating of lamps on a more logical basis.

Any departure from a practice so long in use as the horizontal rating must necessarily be accompanied by some difficulties and confusion, but comparatively little study is necessary to show conclusively that a change is needed and well worth the serious effort of those in position to advance the movement.

A change from horizontal to spherical candlepower would presumably be comparatively easy and free from confusion, but substantial reasons are obvious why the adoption of spherical candlepower ratings would be quite undesirable. The adoption of a comparatively new basis in terms of lumens must naturally be somewhat more confusing, but the logical advantages of this unit have simply to be better understood to be appreciated.

The very clear and concise explanation given of the use of the word lumen, and the easy method of transferring from candlepower to lumens should be of marked assistance to those to whom the subject has not been entirely clear before.

The fact that the mean horizontal candlepower value has simply to be multiplied by the advertised reduction factor and this in turn multiplied by the factor 12:57 to give the total flux of light emitted in terms of lumens, is a method more simple. than has been appreciated by many who may have become confused in trying to deal with the new word.

The line of least resistance is obviously one naturally followed and a departure from long established practice will

naturally take some time and require considerable effort but I believe that the reference in the report to this matter will be very helpful The reference to the correcting of the equally allonical practice of referring to "ethoency" is also truely and we'l worthy of emphasis The phrase lumens per watt" is c'eath so much more logical and true as an expression of eft mency than 'watts per candle" that it would seem a pity not to revise our former practice at this time in connection with the new basis of ratu g, and I am personally in hopes of seeing t'e new officiency expression gam rapidly in use

As central station_re; resentatives we will presumably find it necessary to talk with our customers in terms of candlepower for a considerable time yet but this does not mean that we shonid not cultivate among ourselves and with the public, as rated'y as possible, the knowledge and use of the new basts of Lamp rating in or ler that the time may soon come when lumens shall be spoken of as freely and inteligently as candlep wer is spoken of to day

MR MODEL PLAIN, Syracuse, NY. As usual, this is a very able rej»-rt One thing that is very noticable, however, is that whereas in the past the report of the Lamp Costuitlee las mvariably strongly recommende 1 the continuance at 1 extengen of the tree renewal policy, this report is very moderate T'as shows progress on the subi in its qtscission on t'e jent of the iect, for in my og mon, the free renewal of lamps is a rel dark ages of the lilting industry and a poli v which is 1 be discarded is fast as postbie It is an economically unsoun ! There is no more lo, al reason for

to say the least

s than there is for giving away flat irons

• of aGV ther electrical ap; lances

I heartily wittert. Mr. Ma beth's suggestion that entral stations devote their attention pore to the B, heng bosness an | less to the lamp hasness

MK S B Baas Newark, NJ In this retort it scened that the way is shown for an u pro.e ent in the ap fication of our units There are photo, rand s så man of the pr It has been my experien e in the and in proper use of light central station industry that the un't developement Las fr preceded the accessory development, and that glassware and

fixtures have followed on the heels of our lamps. Perhaps that is the cause of the abuse of our present type C units. I would therefore suggest that it might be of value to correlate the efforts of the gear and fixture manufacturers with the work of the central stations and lamp manufacturers, so that the market may be ready for the new developments now being considered.

MR. J. A. HOEVELER, Chicago: This matter of rating lamps in lumens has been advocated for some time and, so far as I know, the lamp manufacturers are in favor of thus rating, since it gives directly the luminous output of the lamp without further calculations.

If all light sources distributed the flux of light uniformly, a candlepower rating would serve as a fair method of comparing the output of the different lamps. Since this is not the case, it is necessary to resort to the use of the mean spherical candlepower rating, if the rating should truly indicate the luminous output of the lamp. At the present time the lamp companies are rating the specific consumption of the new gas-filled lamps in watts per spherical candle only, and in the case of the vacuum type lamps in both watts per spherical candle and watts per mean horizontal candlepower.

However, in the common methods employed in making illumination calculations today, it is very essential that the illuminating engineer deal with the luminous output of the lamps in lumens. This results in greater convenience and speed in making calculations, because of the close relation that exists between the lumen and the foot-candle. When it is remembered that the foot-candle is equal to an illumination intensity of one lumen per square foot of surface lighted, all that is necessary to determine the intensity of illumination which will be delivered to a given surface by a given lamp, is to divide the total lumens delivered by the lamp to this surface by the area of the surface. The resulting quantity is the average illumination in foot-candles. This is the usual method employed for ordinary illumination calculations, and it will therefore be apparent to your Committee what a distinct advantage it is to the illuminating engineer to rate lamps in lumens. Even with the present rating, every engineer must acquaint himself with the lumens output of the various lamps he deals with.

MR SMITH (closure); Because of the lateness of the hour and the amount of time already consumed in the presentation and discussion of the report I will take the time of the delegates only to say that the Lamp Committee appreciates sincerely the interest that has been shown in its report, and that note has been made of the several suggestions offered, all of which will be interesting and valuable and, your Committee hopes, profitable for future consideration,

REPORT OF COMMITTEE ON ELECTRIC

RANGES

WR PUTNAM, CHAIRMAN

DISCUSSION

MR. PUTNAM (continuing): I want to read just a few extracts from an article which I received the day before I left home. This article has been prepared by a professor in the Utah Agricultural College in our State, and is to be issued as a Bulletin to be sent out to all of the people on the mailing list of the College. Strange to say, it has been done without any effort on the part of the central station.

The subject of the bulletin is "The Electric Range." It has not been printed but I understand it will be.

Professor Humphreys had a number of students in college go out and make a study of some 42 range installations in a town of 8000 people, and this article gives the results and conclusions they reached from that study. I will quote from it.

"Our observations show that the electric range is being used under the following conditions:

(1) The range is used for all the cooking, the kitchen and other rooms being heated with furnaces of some type. Water is heated in winter by furnaces, and in summer by small stove or coal ranges. The hot-water tank in some cases is covered with asbestos to hold the heat.

(2) Both coal and electric ranges are used in the kitchens, the coal range being used to heat the kitchen, heat water and do general cooking during the winter time and to heat water only in the summer months. The electric range is used principally for baking during the winter months and for all cooking during the summer time.

(3) The coal range is used to heat the kitchen and water and, in connection with the electric range, for general cooking both winter and summer.

(SEE REPORT, PAGE 154)