Extraordinary Pieces of Clock-Work.—Amongst the modern clocks, those at Strasburg and Lyons are very eminent for the richness and variety of their furniture, and for their motions and figures. In the former, a cock claps his wings, and proclaims the hour, and an angel opens a door, and salutes the Virgin; while the Holy Spirit descends on her, &c. In the latter, two horsemen encounter, and beat the hour on each other; a door opens, and there appears on the theatre the Virgin, with Jesus Christ in her arms; the Magi, with their retinue, marching in order, and presenting their gifts; two trumpeters sounding all the while to proclaim the procession.
These, however, are excelled by two which were lately made by English artists, and sent as a present from the East India Company to the Emperor of China. These clocks are in the form of chariots, in which are placed, in a fine attitude, a lady, leaning her right hand upon a part of the chariot, under which is a clock of curious workmanship, little larger than a shilling, that strikes and repeats, and goes eight days. Upon her finger sits a bird finely modelled, and set with diamonds and rubies, with its wings expanded in a flying posture, and it actually flutters for a considerable time on touching a diamond button below it; the body of the bird (which contains part of the wheels that in a manner give life to it) is not the bigness of the 16th part of an inch. The lady holds in her left hand a gold tube not much thicker than a large pin, on the top of which is a small round box, to which a circular ornament, set with diamonds not larger than a sixpence, is fixed, which goes round nearly three hours in a constant regular motion. Over the lady’s head, supported by a small fluted pillar not bigger than a quill, are two umbrellas, under the largest of which a bell is fixed, at a considerable distance from the clock, and seems to have no connection with it; but from which a communication is secretly conveyed to a hammer that regularly strikes the hour, and repeats the same to the clock below. At the feet of the lady is a golden dog; before which, from the point of the chariot, are two birds fixed on spiral springs, the wings and feathers of which are set with stones of various colours, and appear as if flying away with the chariot, which, from another secret motion, is continued to run in a straight, circular, or any other direction; while a boy that lays hold of the chariot behind, seems also to push it forward. Above the umbrella are flowers and ornaments of precious stones; and it terminates with a flying dragon set in the same manner. The whole is of gold, most curiously executed, and embellished with rubies and pearls.
Heidelberg Clock.—At Heidelberg, in Germany, upon the town-house, was a clock with divers motions; and when the clock struck, the figure of an old man pulled off his hat, a cock crowed, and clapped his wings, soldiers fought with one another, &c.: but this curious piece of workmanship, with the castle and town, were burnt by the French, who committed at the same time the most inhuman barbarities upon the people, when they took those garrisons, in the year 1693.
Strasburg Clock.—At Strasburg, there is a clock, of all others the most famous, invented by Conradus Dasipodius, in the year 1573. Before the clock stands a globe on the ground, shewing the motions of the heavenly bodies. The heavens are carried about by the first mover, in twenty-four hours; Saturn, by his proper motion, is carried about in thirty years; Jupiter in twelve, Mars in two, the Sun, Mercury, and Venus, in one year; and the Moon in one month. In the clock itself there are two tables on the right and left hand, shewing the eclipses of the Sun and Moon from the year 1573, to the year 1624. The third table in the middle is divided into three parts. In the first part, the statue of Apollo and Diana shews the course of the year, and the day thereof, being carried about in one year; the second part shews the year of our Lord, and the equinoctial days, the hours of each day, the minutes of each hour, Easter-day, and all other feasts, and the Dominical Letter. The third part has the geographical description of all Germany, and particularly of Strasburg, with the names of the inventor, and of all the workmen. In the middle frame of the clock is an astrolabe, shewing the sign in which each planet is every day, and there are the statues of the seven planets, upon a round piece of iron, lying flat; so that every day the statue of the planet that rules the day comes forth, the rest being hid within the frames, till they come out by course at their day, as the sun upon Sunday, and so for all the week. And there is also a terrestrial globe, which shews the quarter, the half hour, and the minutes. There is also the skull of a dead man, and statues of two boys, one of whom turns the hour-glass when the clock has struck, the other puts forth the rod in his hand at each stroke of the clock. Moreover, there are the statues of the Spring, Summer, Autumn, and Winter, and many observations of the moon.
In the upper part of the clock are four old men’s statues, which strike the quarters of the hour; the statue of Death comes out at each quarter to strike, but is driven back by the statue of Christ, with a spear in his hand, for three-quarters; but in the fourth quarter, that of Christ goes back, and that of Death strikes the hour, with a bone in his hand, and then the chimes sound. On the top of the clock is an image of a cock, which twice in the day cries aloud, and claps his wings. Besides, this clock is decked with many rare pictures: and being on the inside of the church, carries another frame to the outside of the wall, wherein the hours of the sun, the courses of the moon, the length of the day, and such other things, are set out with great art.
Clepsydra—is a water-clock, or instrument to measure time by the fall of a certain quantity of water, and is constructed on the following principles.—Suppose a cylindrical vessel, whose charge of water flows out in twelve hours, were required to be divided into parts, to be discharged each hour. 1. As the part of time is to the whole time, Twelve, so is the same time Twelve to a fourth proportional Hundred-and-forty-four. Divide the altitude of the vessel into one hundred and forty-four equal parts: here the last will fall to the last hour; the three next above, to the last part but one; the five next, to the tenth hour; lastly, the twenty-three last to the first hour. For since the times increase in the series of the natural numbers 1, 2, 3, 4, 5, &c. and the altitudes, if the numeration be in a retrograde order from the twelfth hour, increase in the series of the unequal numbers 1, 3, 5, 7, 9, &c. the altitudes computed from the twelfth hour will be as the squares of the times 1, 4, 9, 16, 25, &c. Therefore the squares of the whole time, one hundred and forty-four, comprehend all the parts of the altitude of the vessel to be emptied. But a third proportional to 1 and 12, is the square of twelve, and consequently it is the number of equal parts in which the altitude is to be distributed, according to the series of the unequal numbers, through the equal interval of hours.
There were many kinds of clepsydræ among the ancients; but they all had this in common, that the water ran generally through a narrow passage, from one vessel to another, and in the lower was a piece of cork, or light wood, which, as the vessel filled, rose up by degrees, and shewed the hour.
We shall in the next place make a few remarks on the Invention of Watches.—The invention of spring or pocket watches belongs to the 17th century. It is true, we find mention made of a watch presented to Charles V. in the history of that prince: but this, in all probability, was no more than a kind of clock to be set on a table, some resemblance whereof we have still remaining in the ancient pieces made before the year 1670. There was also a story of a watch having been discovered in Scotland, belonging to King Robert Bruce; but this we believe has turned out altogether erroneous. The glory of this very useful invention lies between Dr. Hooke and M. Huygens; but to which of them it properly belongs, has been greatly disputed; the English ascribing it to the former, and the French, Dutch, &c. to the latter. Mr. Derham, in his Artificial Clockmaker, says, roundly, that Dr. Hooke was the inventor; and adds, that he contrived various ways of regulation. One way was, with a loadstone; another with a tender straight spring, one end whereof played backwards and forwards with the balance, so that the balance was to the spring as the bob to a pendulum, and the spring as the rod thereof. A third method was, with two balances, of which there were divers sorts; some having a spiral spring to the balance for a regulator, and others not. But the way that prevailed, and which still continues to prevail, was, with one balance, and one spring running round the upper part of the verge; though this has a disadvantage, from which those with two springs, &c. were free, since a sudden jerk, or confused shake, will alter its vibrations, and disturb its motion.
The time of these inventions was about the year 1658; as appears, among other evidences, from an inscription on one of the double-balance watches presented to King Charles II. viz. “Rob. Hooke inven. 1658. T. Tompion fecit, 1675.” The invention presently got into reputation, both at home and abroad: and two of them were sent for by the dauphin of France. Soon after this, M. Huygens’ watch with a spiral spring got abroad, and made a great noise in England, as if the longitude could be found by it. It is certain, however, that his invention was later than the year 1673, when his book “De Horol. Oscillat.” was published; wherein he has not one word of this, though he has of several other contrivances in the same way.
One of these the Lord Brouncker sent for out of France, where M. Huygens had got a patent for them. This watch agreed with Dr. Hooke’s, in the application of the spring to the balance; only M. Huygens’ had a long spiral spring, and the pulses and beats were much slower. The balance, instead of turning quite round, as Dr. Hooke’s, turns several rounds every vibration.