The Wonder Book of Knowledge / The Marvels of Modern Industry and Invention, the Interesting Stories of Common Things, the Mysterious Processes of Nature Simply Explained

by Unknown

[47] Courtesy of James Boyd & Bro., Inc.

[48] Courtesy of American LaFrance Fire Engine Co.

[49] Courtesy of American LaFrance Fire Engine Co.

[50] Courtesy of American LaFrance Fire Engine Co.

[51] Courtesy of American LaFrance Fire Engine Co.

[52] Illustrations by courtesy of American Cyanamid Company.

[53] Courtesy of The Strauss Bascule Bridge Co.

[54] Courtesy of The American Magazine.

[55] Illustrations by courtesy of the Railway Age Gazette and Standard Steel Car Co.

[56] Illustrations by courtesy of Diamond Crystal Salt Co.