DEVELOPMENTS IN ILLUMINATION—MILLAR., 617 
One illuminant has been produced which yields light of a color 
closely approximating what may be considered to be average day- 
light. That is the Moore carbon-dioxide tube. Mazda lamps, the 
intensified carbon are lamp, and gas mantle lamps have been equipped 
with color screens intended to modify the light to produce artificial 
daylight.t_ Some of these duplications of natural light are excellent 
and are being employed with good effect for commercial purposes. 
Other illuminants or equipments for illuminants have been announced 
as the equivalent of daylight or as having daylight qualities. Unfor- 
tunately, however, there has been much misrepresentation connected 
with this, and so far as the writer is aware, only the efforts named 
above should be regarded seriously in this connection. 
CHRONOLOGIGAL DIAGRAM OF GAS LAMPS 
+ PRESSED GAS 
S PER ” FT. os HR. 
S 
ar} 
THORIA-CERIA MANTLE+ 
1 | 
+ WELSBACH UPRIGHT 
8 
OPEN FLAME 
BURNER 
° 
130 & 4 c 6 1990 2 4 G 6 1900 @ 4 c 8 i810 2 + 
Fia. 5. 
Lighting auxiliaries,” including reflectors, globes, shades, etc., have 
been greatly improved in recent years. Plate 1, figure 1, illustrates 
some types of reflectors typical of those which were sold 10 to 15 
years ago. Plate 1, figure 2, shows an assortment of modern 
reflectors which surpass those previously available in appearance, 
and in that they conceal the light source and diffuse the light. They 
excel also in efficiency of light redirection. 
The design and manufacture of fixtures * may be divided into two 
classes; namely, fixtures of distinctive design and stock fixtures. 
The former can not well be generalized; the latter, which, of course, 
1 Artificial daylight illuminants: ‘‘A standard for color values—The white Moore light,” Moore; Trans. 
Illg. Eng. Soc., 1910, p. 209. ‘‘A lamp for artificial daylight;’’ Hussey; Trans, Illg. Eng. Soc., 1912, p. 73. 
“Subtractive production of artificial daylight;” Ives and Luckiesch; Electrical World, 1911, p. 1092. “A 
gas artificial daylight;’’ Ives and Brady; Lighting Journal, 1913, p. 131. 
2 Auxiliaries: ‘‘The principles of shades and reflectors;’’ Bell; Trans. Illg. Eng. Soc., 1909, p. 723. ‘‘Sei- 
entific principles of globes and reflectors;’? Lansingh; Trans. lg. Eng. Soc., 1910, p. 49. “Symposium 
on illuminating glassware;’’? Jones, Marshall, Young, and Hibben; Trans. Illg. Eng. Soc., 1911, p. 854. 
3 Fixtures: “‘Fixture design,” Lansingh and Heck; Trans. lg. Eng. Soc., 1907, pp. 728-784. “The 
relation of fixture design to modern illuminating practice ’? Hopton and Watkins; Trans. Illg. Eng. Soc. 
1910, p 310. 
