Part 3

A group of oil-lamps of two centuries ago 33

Lamps of a century or two ago 56

Elaborate fixtures of the age of candles 57

Flame arc 128

Direct current arc 128

On the testing-racks of the manufacturer of incandescent filament lamps 129

Carbon-dioxide tube for accurate color-matching 160

The Moore nitrogen tube 160

Modern street lighting 161

A completed lighthouse lens 176

Torro Point Lighthouse, Panama Canal 176

American search-light position on Western Front in 1919 177

American standard field search-light and power unit 177

Signal-light for airplane 232

Trench light-signaling outfit 232

Aviation field light-signal projector 232

Signal search-light for airplane 232

Unsafe, unproductive lighting worthy of the dark ages 233

The same factory made safe, cheerful, and more productive by modern lighting 233

Locomotive electric headlight 240

Search-light on a fire-boat 240

Building ships under artificial light at Hog Island Shipyard 241

Artificial light in photography 256

Sterilizing water with radiant energy from quartz mercury-arcs 257

Judging color under artificial daylight 272

Artificial daylight 273

Fireworks and illuminated battle-fleet at Hudson-Fulton Celebration 288

Fireworks exhibition on May Day at Panama-Pacific Exposition 289