It is hard to realize that nearly a hundred years must have passed by before the hair-spring came into common use. To-day any new device is described in catalogs, written up in the papers, manufactured in quantities and is quickly carried by travelers into every country, but in those days everything was still made by hand, piece by piece, and there was comparatively little travel that would admit of its distribution. Ideas made their way very slowly. In fact, Julien Le Roy rediscovered the principle of isochronism and announced it with a good deal of pride, quite ignorant of the fact that Hooke and Huyghens explained it nearly a century before. And so the hair-spring was slowly adopted by English watchmakers with a number of minor improvements. Other inventors, of whom presently we shall hear more, worked out better methods of escapement, and the watch movement developed slowly toward its present form. It became possible to tell time more accurately and to make arrangements and plans more closely as the watch became a better time-keeper. The pace of life was speeding up, and people were realizing the value of minutes—even of seconds. Therefore the minute- and second-hands were added to the hour-hand that so long had moved alone around the watch-dial. And in 1704, Nicholas Facio, a Swiss doing business in London, introduced jeweled bearings into the mechanism. The importance of jewels is often misunderstood even at the present day. Many people do not know why jewels are used in a watch, assuming that they are intended for ornament or in some way to increase the value. But most of the jewels in a watch-movement are placed out of sight; and, although they often consist of real rubies or sapphires, they are so tiny and their intrinsic value so small that no watch requires more than one dollar's worth of jewels. They are strictly utilitarian in their purpose. A pivot or bearing, running in a hole drilled in a jewel, creates almost no friction and requires so little oil that a single drop as big as a pinhead is enough for an entire watch. Because jewels are so hard and smooth, a watch with jeweled bearings runs better and wears less and requires less power to drive it, than one in which they are lacking. During all the time recounted, the great mainspring of civilization had been pressing, ever pressing. Nothing could be considered "good enough" if a way could be found to improve it. At last an improvement came out of the sea. Travel had been reaching out in every direction; ships were fitted out by scores to take goods from England or the continent of Europe to lands across the seas and to bring back the products of these countries.