[Picture Diagram Showing How Electricity is Generated]
[Picture Diagram Explaining Radioactivity]
[Map of Panama Canal and Connections]
Other Full Page and Text Illustrations
These include hundreds of beautiful and instructive reproductions illustrative of the heavens, earth, minerals, plants and plant products, animal life, races and peoples, famous examples of architecture, scenes in great cities, historic shrines and ruins, mythology, science, marvels of mechanism, great works of engineering, monuments, industries, etc., as well as numerous photographic and art pictures of famous persons and episodes in the history of progress.