| The Majestic, Largest Steamship in the World | [Frontispiece] |
|---|---|
| FACING PAGE | |
| Eohippus—From Which the Modern Horse Developed | [16] |
| Ornitholestes—A Prehistoric Animal of America | [17] |
| Huntsman, Horse, and Hunting Dog of Long Ago—From an Ancient Cretan Fresco | [17] |
| Prehistoric Paintings—An Exhibition of Copies from the Cavern at Altamira, Spain | [24] |
| Saber-Toothed Tiger That Once Roamed Over North America | [25] |
| Gutenberg's Printing Presses—Models on Exhibition | [32] |
| Benjamin Franklin's Printing Press | [33] |
| Model of the "Santa Maria," the Flagship of Columbus | [48] |
| Curtiss Navy Racer, the Airplane That Won the Pulitzer Race of 1921 | [49] |
| U. S. Army Dirigible on a Transcontinental Flight | [49] |
| Electric Motor of 1834 | [64] |
| Turning Lathe of 1843 | [64] |
| Edison Phonograph of 1878 | [65] |
| Whitney's Cotton Gin | [65] |
| De Witt Clinton Train of 1831 Beside a Modern Locomotive | [80] |
| Locomotive of the 1870 Period | [81] |
| "John Bull," a Locomotive Brought from England in 1831 | [81] |
| Weather and Astronomical Instruments on the Roof of Greenwich Observatory, England | [112] |
| Mooring Tower for Airships, with the "R-24" Fastened Head On | [113] |
| Hospital Room in Which Infected Articles Are Sterilized | [160] |
| Modern Operating Room in Paris, Fitted with a Glass Dome and Radio Microphones for Observing Students and Doctors | [161] |
| Edouard Belin and the Telautograph, which Transmits Pictures by Wire | [176] |
| Lee De Forest, Inventor of the Oscillating Audion | [177] |
| Automobile with Radio Equipment for Listening in En Tour | [177] |
| Gifts for Tutankhamen Brought by One of his Viceroys | [192] |
| Tutankhamen's Tomb—Bringing Up the Hathor Couch | [193] |
| Queen Nefertiti, Mother-in-Law of Tutankhamen and Wife of Ahknaton | [193] |
HOW TO USE THE POPULAR SCIENCE LIBRARY
This series of books is written for all the people and not for specialists only, though it is the work of specialists who know how to explain their subjects clearly and interestingly, without unnecessary technicalities and with keen appreciation of the popular and constantly increasing desire for scientific knowledge.
The supreme importance of science in the wonderful age in which our lot has been cast was demonstrated with overwhelming force of conviction by the events of the World War. If, as certain persons assert, science may be accused of having rendered war more destructive and terrible, yet, on the other hand, no one can deny that it was science that saved the world from sliding backward into an age of despotism.
The true importance of science for everybody arises from its rapidly increasing service in the development of human industry in all its forms, for industry is the mother of democracy.
Said Gabriel Lippman, the French physicist, inventor of color photography, who died in the summer of 1921: "For thousands of years science progressed by groping and feeling its way, and coincidentally industry got slowly on by guesswork; but within the last century science has developed more than during all preceding time, while industry has sprung upon its feet and begun to march with the strides of a giant."
Notwithstanding its immense importance and the vast extent and complication of its application in modern times, science is not really difficult for any person of ordinary school education and of good natural intelligence to comprehend, provided it is presented in a clear, plain, common sense manner, in popular language with illustrations drawn from everyday life and experience. The much talked-of methods of science are, after all, nothing more than the methods of common sense, applied with systematic care by minds disciplined to a high degree of efficiency. And, in fact, the only practical difference between the mind of a trained scientist and that of any other intelligent person is that the scientist has acquired a way or habit of looking at and thinking about things and events, which enables him to get at their inmost nature and meaning more swiftly and accurately than he could do if he went to work in a haphazard manner as, in truth, his forerunners of the earlier centuries were obliged to do. The pioneer must always work by rule of thumb, but when he has exploited his field he knows better ways.
Each branch of science has its own particular methods, but it is not necessary for the average reader to study these special methods in order to become able to grasp the facts and principles that have been developed by them. The results are all thrown into a common store—or should be if science is to attain its utmost usefulness to humanity—and from the common store the great public, the people at large, should be enabled freely to draw. The object of this series of books is to form such a store of science for the people.