DEVELOPMENTS IN ILLUMINATION—MILLAR. 625 
moting trade, and have had recourse to display street lighting to 
supplement the lighting provided by the city. Thus, tungsten clus- 
ter lighting has been installed in many cities, particularly the smaller 
cities of the country, with a very beneficial effect upon street lighting 
asa whole. More recently a competitive form of illumination, known 
as the ornamental arc lamp system, in which an inverted arc lamp 
is employed, has commanded much attention and is experiencing 
notable growth. General civic street lighting is improving slowly, 
the average standard of intensities being increased, and somewhat 
better design of the illuminants and systems being noted in the more 
recent installations. 
There is some little development in the way of lighting exteriors of 
buildings. Outline lighting of expositions was first carried out in a 
notable manner at the Columbian Exposition in 1893, attaining per- 
haps its highest development at the Pan-American Exposition in 
Buffalo in 1901. The Jamestown Exposition struck a new note in 
lighting building exteriors, and in the Panama-Pacific International 
Exposition in San Francisco, 1915, we are promised a fuller develop- 
ment of the lighting of buildings by concealed sources. 
These occasional remarkable installations are, of course, few in 
number. There is no general tendency to light the exteriors of 
buildings, though a few creditable attempts have been made in this 
direction. 
PROGRESS IN ILLUMINATION. 
Having reviewed briefly the recent developments in the field of 
illumination, allow me to direct your attention briefly to the subject 
of progress and to 
the forces which PROGRESS IN ILLUMINATION 
ART OF ILLUMINATION ILLUMINATING PRACTICE 
have been respon- 
sible for improve- 
ments in the past 
and to which we 
must look for fur- 
ther development. 
The illumination 
which is provided 
depends not only 
upon the status of 
the art but also 
upon the degree to 
which practice con- Fels, 
forms with the art. 
It has been stated that the art of illumination is improved as the 
materials of illumination are bettered and as the science of illumina- 
tion is advanced. It may now be added that illuminating practice 
is improved as individuals, manufacturers in the lighting field, con- 
73176°—sm 191440 
MATERIALS 
SCIENCE 
INDIVIDUAL 
MANUFACTURER 
CONTRACTOR 
LIGHTING CO. 
