ments employing lamps of higher power have also been !, while the high-power standard lamps, with metal reflectors f the industrial type, have received consideration where lamps are pla ed closely, as in illuminating signs.

a were the Massa hasetts State H e at Eston, Ig 16 u ated during Flethal Property Week, an!te Wolth :. New York, Fig 17.

The practicability of flood lighting is shown by the following list of applications where this method has proved successful:

Electric lighting is becoming quite the thing in portrait studios, with the advantage that a studio can be selected without

to a skylight, and the time of exposure can be mo at detern med Mazda lamps are used either in an arti

tor individual reflectors.

stallations have also been made in moving picture A few of these have employed all mazda laps but in % of cases they have been used in consunction with y vator lamps, which have relatively high actinicity As have been made with photo grat lie le tiste !

employ fairly high-current arc lamps or some type of gas generator and lamp. These equipments were expensive, not simple to operate, and there was a certain element of risk. Focus type incandescent lamps, however, are extremely safe, economical, convenient and simple to operate. Various sizes of lamps are standard so that the small stereopticon in the home can be operated at a minimum cost, or the larger machine in the hall or theatre can furnish good illumination.

Even with the moving picture machine a number of the small models are now equipped with mazda lamps of special filament concentration, and inquiries from operators of larger machines indicate a strong demand for an incandescent lamp as soon as the development is ready for application.

Outdoor Sports at Night

The growth of this phase of lighting has been marked. In almost every locality there is at least one artificially illuminated tennis court. A number of systems have been devised for this particular problem and these have, in general, all proved satisfactory. Trap-shooting, golf, polo, hockey, open-air horse shows, theatricals, playgrounds and exhibitions of various characters have been successfully lighted with regular lamps in the standard industrial reflectors or by means of flood-lighting units.

Stage

The developments in stage lighting equipment are proceeding at a remarkable rate. The high candlepower mazda C lamps in suitable reflecting devices are rapidly replacing the old-style hand-fed open arc lamp. The convenience of control and greater safety of the new light sources have been important factors in its introduction. Whereas formerly a man had to be stationed at each group of arc lamps, now all units can be controlled from the main switchboard. The fact that the distribution of light from incandescent lamps can be accurately controlled by reflectors of the proper contours has made possible effects which heretofore were almost beyond the ability of the ingenious stage electrician. Valuable research has been carried on investigating the color effects that it is possible to secure with scenery properly dyed and with the light suitably filtered.

al Daylight

The need for reproducing artificial daylight for special uses and for special uses in the daytime where natural ligh aled has brought about several more or less successful s at the production of artificial daylight. The Moore dixile tube is the original device which entered successmta commercial practice. In the last five or six years sev er artificial daylight equipments have been developed, g one intensified carbon are lamp with color filter, and a ⚫er utilizing mazda Clamps with color filters. At the present

ere is available a variety of equipments many of which se certam purposes and no one of which is likely to serve all - ses required of an artibial equivalent of natural light ...he information on this subject which is presented by the "ce appears in Fig 19 in the form of spectrophotometrie These shows the relative intensity of light of each wave

gut the visible spectrum For practical purposes zontal line bearing the value of 100 may be considered resent white light The illumanants re; resented by curves

w high values in light of the short wave lengths (the 1 of the spectrum) and relatively low values in light of have lengtis athe red end of the spe trum) produce light 1 relatively bluer than this standard The luminants bare represented by curves showing 1 wer intensities in the

h gier i tersities in the red are redder than this stand 19 d “ault to convey an idea of t'e pra tid effect of rid Herences, boat if it is remebered that Carve F ten resents the light from a raz la vacuum lanp, Curve A direct gt and Curve B north sky "git, a retalle 1'ea half the difteren es mvive!

dering this question it must be remen here ! that dayd variable quality, ranging from Nish W de b, ht from * dy on a dear day to the rel

Ives® . werving that the the

et the ville spectrum fra } molite is elisely the equivalent of en ereth has proposed the distribution of be

etrum from such Mak l !.

! wh.h to express quality of daylight

w hight of the

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