It was in this decade that the gyroscope emerged from the laboratory and toy shop and began to be applied to practical uses. Schlick utilized the gyroscope to prevent ships from rolling. The gyrocompass was invented and reached a commercial stage in 1910. 1911-1920 It is difficult to pick out the most important inventions of this decade because sufficient time has not elapsed to determine which are most deserving of mention. The Great World War stimulated invention in all civilized lands. Aeronautics developed faster in the five years of war than it could in twenty-five years of peace. Of course, engines of war developed to a remarkable degree. Among the lighter pieces we saw the development of the Lewis gun, and then the Browning gun. The most important invention was the tank. Many advances should be classed as remarkable developments rather than basically new inventions. The war of and against the submarine brought forth many ingenious devices. Of the peace-time inventions, the most remarkable is the optophone, the instrument which enables the blind to read ordinary printed matter. * * * * * And thus the march of progress continues unchecked. We are tempted to give our imaginations free play and forecast the developments that the future holds in store for us, but unfortunately we cannot claim any prophetic instinct or inspiration. TRANSCRIBER’S NOTE: --Obvious print and punctuation errors were corrected. End of the Project Gutenberg EBook of Mechanics, by A. Russell Bond