Inventions in the Century

by William Henry Doolittle

Then followed the famous observation of the swinging lamp by the then young Galileo, about 1582, while lounging in the cathedral of Pisa. The isochronism of the vibrations of the pendulum inferred from this observation was not published or put to practical application in clocks for nearly sixty years afterward. In 1639 Galileo, then old and blind, dictated to his son one of his books in which he discussed the isochronal properties of oscillating bodies, and their adaptation as time measures. He and others had used the pendulum for dividing time, but moved it by hand and counted its vibrations. But Huygens, the great Dutch scientist, about 1556 was the first to explain the principles and properties of the pendulum as a time measurer and to apply it most successfully to clocks. His application of it was to the old clock of Vick’s.

The seventeenth century thus opened up a new era in clock and watch making. The investigations, discoveries, and inventions of Huygens and other Dutch clock-makers, of Dr. Hooke and David Ramsey of England, Hautefeuille of France, and a few others placed the art of clock and watch making on the scientific basis on which it has ever since rested.

The pendulum and watch-springs needed to have their movements controlled and balanced by better escapements. Huygens thought that the pendulum should be long and swing in a cycloidal course, but Dr. Hooke found the better way to produce perfect isochronous movements was to cause the pendulum to swing in short arcs, which he accomplished by his invention of the anchor escapement.

The fusee which Dr. Hooke re-invented consists of a conical spirally-grooved pulley, around which a chain is wound, and which is connected at one end to a barrel, in which the main actuating spring is tightly coiled. The fusee is thus interposed between the wheel train and the spring to equalise the power of the latter.

To Dr. Hooke must also be credited the invention of that delicate but efficient device, the hair-spring balance for watches. His inventions in this line were directed to the best means of utilising and controlling the force of springs, his motto being “ut tensio sic vis,” (as the tension is so is the force.) Repeating watches to strike the hours, half-hours and quarters, made their appearance in the seventeenth century. In the next century Arnold made one for George III., as small as an English sixpence. This repeated the hours, halves and quarters, and in it for the first time in the art a jewel was used as a bearing for the arbors, and this particular one was a ruby made into a minute cylinder.

After the discovery and practical application of weights, springs, wheels, levers and escapements to time mechanisms, subsequent inventions, numerous as they have been, have consisted chiefly, not in the discovery of new principles, but in new methods in the application of old ones. Prior to the eighteenth century, however, clocks were cumbrous and expensive, and the watches rightly regarded as costly toys; and as to their accuracy in time-measuring, the cheaper ones were hardly as satisfactory as the ancient sun-dials.

With the coming of the machine inventions and the new industrial and social ideas of the eighteenth century came an almost sudden new appreciation of the value of time. Hours, minutes and seconds began to be carefully prized, both by the trades and professions, and the demand from the common people for accurate time records became great. This demand it has been the office of the nineteenth century to supply, and to place clocks and watches within the reach of the poor as well as the rich. While thus lessening the cost of time-keepers their value has been enhanced by increasing their accuracy and durability.

Among the other ideas for which the eighteenth century was famous in watch-making was that of dispensing with the key for winding, thus saving the losing of keys and preventing access of dust, an idea which, however, was perfected only in the last half of the nineteenth century.

The eighteenth century was chiefly distinguished by its scientific improvements in time-keepers, to adapt them for astronomical observations and for use at sea, in not only accurately determining the time, but the degrees of longitude. Chronometers were invented, distinguished from watches and clocks, by means by which the fluctuation of the parts caused by the variations in temperature are obviated or compensated. In clocks what are known as the mercurial and gridiron pendulums were invented respectively toward the close of the eighteenth century by Graham and Harrison, and the latter also subsequently invented the expanding and contracting balance wheel for watches. The principle in these appliances is the employment of two different metals which expand unequally, and thus maintain an uniformity of operation.

The Dutch, with Huygens in the lead, were long among the leading clock-makers. Germany ranked next. It was in the seventeenth century that a wonderful industry in clock-making there commenced, which lasted for two centuries. The Black Forest region of South Germany became a famous locality for the manufacture of cheap wooden clocks. The system adopted was a minute division of labour. From fourteen to twenty thousand hands twenty years ago were employed in the Schwarzwald district. Labour-saving machines were ignored almost entirely. The annual production finally reached nearly two million clocks, of the value of about five million dollars.