1090 ILLUMINATION ITEMS Journal A. I. E. E.

extent and it is the intention of the committee to con..tinue the plan of getting the railway operating men tocooperate with us in this way.

The principal afternoon speaker was Mr. L. G. Cole­man, Assistant General Manager of the Boston &Maine Railway, who gave an excellent paper in whichhe painted a graphic picture of the steam locomotive,its virtues and limitations. A number of other opera­ting men joined in the discussion and contributedlargely to the success of the meeting.

The past year has been distinctly one of progress inthe field of the electric railway. No particularlyspectacular events have been noted but there is asteady development going on in all lines which promisesto handle the transportation problem most satisfac­torily when it is finally presented.

Several new types of locomotives have been developedin the past year and improvements have been made inline construction, current collection, distribution sys­tems, etc. Indications are that several large electri­fication projects will be started as soon as the financialsituation will permit the railroads to undertake suchimprovements.

It is recommended for next year that:1. Suitable papers be presented covering the points

brought out in the Philadelphia meeting.2. A suitable paper covering the subject of power

supply for electric railways.3. Papers covering the latest developments in

electric locomotives.4. Papers covering the development of the oil­

·electric or steam-electric locomotive.N. W. STORER,

Chairman.

ILLUMINATION ITEMSBy the Lighting and Illumination Committee

IMPROVEMENTS IN STAGE LIGHTING CONTROLEQUIPMENT .

The application of light-intricate in its many colors'and intensities-to the plot of a theatrical productionhas, within recent years, been developed into a veritableart. The "light plot" of a large production is justas surely an essential factor in its success as are theactions and movements of the actors themselves.The proper use of light on the stage may transform abare set of draperies into almost any scenic illusiondesired. On the other hand a scene may be ruinedas easily by improper lighting as by poor acting.

An example of the control equipment necessary ineffectively bringing forth the grace and beauty of aplay is illustrated in the new Scottish Rite Cathedralin St. Louis. According to the September issue of theElectragist (New York) a total of 600 kw. is distributedequally between the stage, auditorium, and the otherparts of this new building. In this theatre, coloredlights, from the borders, footlights, spot or floodlights

may be used in any possible combination, which can bepre-selected after the light rehearsal and thrown on bya single lever at the proper moment during the play.This is done through the utilization of one of threeprogram switches, each of which has 48 contact points.Each of these points is connected to the operating coilof a remote control switch and the selection of pointsis accomplished by the use of a fiber card with holespunched in it corresponding to the desired contactpoints in a given combination.

The three program switches are connected in parallelso that a practically unlimited number of setups canbe obtained in a very short time, provided the desiredfiber cards have been prepared in advance. It is alsopossible to add additional groups of lights to the set-upby individual manually controlled switches. All re­mote control switches are of the magnetically heldtype and by means of a momentary contact lock pushswitch on the pilot board, the entire system can belocked against interference when not in use.

A very unique feature of this installation is themethod of dimming. . For this purpose a choke coil,wound about a core of sheet-steel punchings, is placedin series with the lamps to be dimmed, and the currentin a direct-current winding on the core varies the pointof operation on the saturation curve of the core in sucha manner that when the coil is open the "choking"effect is a maximum, and the lamps are operating on avoltage which is insufficient to furnish any appreciableamount of light. While on the other hand, when thefull voltage of 110 volts is applied to the d-e, coil, thesaturation of the core is so high that the choking effectis decreased to such an extent that the lamps approachtheir normal brilliancy. An auto transformer is usedto overcome the 10 per cent choking effect which cannotbe entirely eliminated in the amplifier dimmer.

Eighty-one of these amplifier dimmers are used andthey take approximately one ampere each of directcurrent for the larger ones and around three quartersof an ampere for the smaller ones. By this methodan accurate method of control is secured in a relativelysmall space.

Even the most scientifically designed reflectors,lenses, and color screens all go for nought if the controlequipment at the switchboard is inadequate or im­properly managed. Such equipment as that mentionedabove permits an ease of control by means of whichlighting effects can be obtained which surpass inbeauty and grace even the wildest dreams of previousyears.

A new church has recently been dedicated in thefamous shop district of Chicago. This churchly edificeis unique, indeed, for it is situated in the business andamusement center of the city. Its cross, 568 feetabove the pavement, is the highest in the history ofthe world. It will be illuminated each night in theyear.