Part 44

Robins, Benjamin, 201

Rome, 30, 32, 34, 39, 41, 42, 44

Roentgen, 270, 280. See also X-ray.

Royal Society of London: 33, 63, 66, 67, 70, 73; and first gas explosion, 75, 111, 112

Rumford, 167

Rushlights, 28, 33

Russia, 281

Ryan, W. D'A., 306

Safety: artificial light in relation to, 14, 225 et seq.

Salts: chemical, 88, 89; metallic, 120; silver, 257, 258

Sandy Hook Light, 165, 166

San Francisco, 304, 306-309

Savages, 3, 15, 17

Sawyer, 129

Scheele, K. W., 133; quoted, 257, 258

Schools, 9

Science: light and, 6, 7; 97; systematized, 268

Scotland: 26, 31, 32, 48; oil industry in, 56

Scott, Sir Walter, cited, 27, 98

Sculpture: artificial light in relation to, 184

Search-lights, 11, 169

Section of Plant Protection, 225, 226

Selenium, 267, 293

Semaphore, 199

Shells: illuminating, 179 et seq.

Shirley, Thomas: quoted on natural gas, 66, 67

Siemens, 78

Signaling, 194-207