Over twenty inventions from the early twentieth century are detailed in this volume. The author organizes the inventions by type, (telephonic, motive, gyroscopic, etc.) and explains the technical innovations. About half of the inventions are of permanent significance, but other have been superseded with new technology. The early twentieth century was a period of fantastic progress in a variety of technical areas.
The object and the scope of this volume have been explained in the Introduction, and the author's indebtedness to inventors, proprietors of inventions, and others has been acknowledged in the Appendix.
The object of this volume is to present to the general reader a clear idea of some of the most interesting inventions of the twentieth century. Although we have not travelled very far into the present century, there has been a host of inventors at work, with varying degrees of success or failure. Since the beginning of 1901, no less than 199,000 patents have been sealed, while the total number of applications lodged has been between 300,000 and 400,000. Hence it goes without saying that the present volume does not include all the inventions of the twentieth century: a mere list of the titles of all these would occupy twenty volumes of this series.
In selecting the sixty inventions with which this volume deals, the guiding principle has been the degree of ingenuity embodied in the invention. We are not concerned whether this or that particular invention is superior for some practical purpose, but rather which is the most ingenious.
The description of what a certain piece of mechanism does is of some interest, but a description of how the desired operations are achieved is of very much greater interest, and so the latter plan has been adopted in the present volume. It will be understood that to describe any complicated invention in non-technical words is necessarily more roundabout than to use technical words, each of which may stand for what must be expressed otherwise in a phrase, a sentence, or even a number of sentences. In order to make the descriptions entirely non-technical, it has been necessary to give the reader a mental picture of each invention. There has been no attempt to treat the subject historically, except where the evolutionary steps have seemed to be necessary towards a complete understanding of the invention.