Part 2
The plane of every dial represents the plane of some great circle on the earth, and the _Gnomon_ the earth's axis; the vertex of a right _Gnomon_, the centre of the earth or visible heavens. The earth itself, compared with its distance from the sun, is considered as a point, and therefore if a small sphere of glass be placed upon any part of the earth's surface so that its axis be parallel to the axis of the earth, and the sphere have such lines upon it, and such plans within it, as above described, it will show the hour of the day as truly as if it were placed at the earth's centre, and the shell of the earth were as transparent as glass. The diversity of the titles of sun-dials arises from the different situation of the planes, and the different figure of the surfaces whereon they are described, whence they are denominated equinoctial, horizontal, vertical, polar, erect, direct, declining, inclining, reclining, cylindrical, &c.
+--------------------------------------------------------------+ | [Illustration: The Pocket Ring Dial.] | +--------------------------------------------------------------+
All the before-mentioned time-measurers were up to a certain period non-portable, and in addition to the drawback of being unserviceable excepting when the weather was clear and the days bright were as useless for private purposes, as they were unadapted for the winter-time or for night. The next step was therefore a portable dial, but this was probably not invented until after a very long interval. The Dial of which the above is an illustration, was probably one of the earliest of portable time-keepers, the time being shown by means of a hole through which the light fell on the inside, which had an inner ring adaptable to the day and the month. Ring-dials of this description were in common use within the last century in this country, and were manufactured in large numbers at Sheffield when watches were too expensive to be generally attainable. Some of these Ring-dials were of superior construction, and were made by means of more than one ring to serve for different latitudes. As an example of a still greater advance in the manufacture of pocket dials, see the illustration on the next page.
The Dial consists of a thin silver plate properly divided and marked, and having a compass with glass cover sunk at one end of it. The _Gnomon_ or style moves upon a hinge so as to allow of its lying flat upon the Dial while in the pocket, and thus rendering the instrument conveniently portable. The _Gnomon_ itself is also susceptible of elevation or depression and the beak of the bird carved on a thin slip of silver at its side marks the exact extent of the _Gnomon's_ elevation. This Dial is indubitably of French manufacture.
One would imagine that it was such a dial as this that Shakspeare had in his mind's eye when he wrote the well-known passage which he put into the mouth of Jaques, wherein that philosophic satirist describes his meeting with a fool in the forest.
+--------------------------------------------------------------------+ | [Illustration: Silver Pocket Dial (in the collection of the Honble | | Company of Clockmakers, London).] | +--------------------------------------------------------------------+
'Good morrow, fool, quoth I. "No sir," quoth he, "Call me not fool till heaven hath sent me fortune; And then he drew _a dial from his poke_, And looking on it with lack-lustre eye, Says, very wisely, "It is ten o'clock: Thus we may see," quoth he, "how the world wags: 'Tis but an hour ago since it was nine, And after one hour more 'twill be eleven. And so from hour to hour we ripe and ripe, And then from hour to hour we rot and rot. And thereby hangs a tale." When I did hear The motley fool thus moral on the time, My lungs began to crow like Chanticleer, That fools should be so deep contemplative; And I did laugh, sans intermission, _An hour by his dial_.'
What the fool's dial was, has given rise to many conjectures, but there is no better authority perhaps on the subject than Mr Halliwell, from whose magnificent and elaborate folio we will make the following very interesting extract.
'The term dial appears to have been applied in Shakspeare's time to anything for measuring time in which the hours were marked, so that the allusion here may be either to a watch, or to a portable journey ring, or small dial. The expression "it is ten o'clock" is not decisive, as it may be considered to be used merely in the sense of the hour thus named. * * * A watch even is sometimes called a clock, * * * and it seems by no means unlikely that the common ring dial which has been in use for several centuries up to a comparatively recent period, should be the dial referred to in the text.'
Whatever may have been the shape of the dial which Jaques saw drawn from the fool's 'poke,' it is an undoubted fact that portable dials did serve the part of time-keepers, and were in their way valuable as such to those who had learnt how to use them. But the dial would not do the work of the watch in an age when people no longer travel by the waggon-load or with pack-horse, but are whirled fifty or sixty miles in that time and have to reckon their engagements not by the day, but by the minute. The world no longer 'wags' in jog-trot style, but speeds at steam-pressure and sends its messages by lightning-conductor; it consequently values its time more highly and measures it more carefully.
The Horologe which possibly next succeeded in date the invention of the Dial, was the Clepsydra or Water-Clock, the precise antiquity of which is however unknown.
+--------------------------------------------------------------------+ | [Illustration: The Clepsydra, or Water-Clock of the Greeks.] | +--------------------------------------------------------------------+
The CLEPSYDRA is so named because the water escapes from it as it were by stealth, but in a regulated flow so as to permit of the lapse of time being computed thereby, even as by sand running through sand-glasses. The Clepsydra appears to have been at first used to limit the time during which persons were allowed to speak in the Athenian Courts of Justice; 'the first water,' says Æschines, 'being given to the accuser, the second to the accused, and the third to the judges,'--a special officer being appointed in the courts for the purpose of watching the Clepsydra and stopping it when any documents were read whereby the speaker was interrupted. The time, and consequently the water allowed, depended upon the importance of the case. This custom, says Phavorinus, was to prevent babbling, that such as spake should be brief in their speeches. Ctesibius of Alexandria, who lived about 245, invented a much improved water-clock, mentioned by Vitruvius and Athenæus. Another kind of Clepsydra consisted of a vessel of water having a hole in it through which the fluid gradually escaped; a miniature boat floated upon the water and descended as the water decreased, whilst an oar placed in the boat indicated the hour by pointing to certain line-marks on the side of the vessel. The hole through which the water dropped was made, we are told, through a pearl, because it was supposed that the action of the water upon the pearl would not, as upon other substances, enlarge the aperture, nor would the pearl, it was imagined, be choked by the adhesion of any other material. The chief fault of the Clepsydra as a chronometer arose from the inequality of the flow of water, it being found to escape more rapidly when the vessel was full than when it was becoming empty, and also more speedily in hot weather than in cold. The Egyptians are however said to have measured by this machine the course of the sun; by it Tycho-Brahe computed the motion of the stars; and by it Dudley made his maritime observations. Plato furnished the original idea of the hydraulic organ by inventing a Clepsydra, or water-clock, which played upon flutes the hours of the night when darkness precluded their being shown by the index. Clepsydræ are still used in India.
The SAND-GLASS, as we have said, is an instrument of the same character as the Clepsydra,--the one measuring time by the fall of water and the other by the running of sand. Sand-glasses are known to have been used 200 B.C. The best hour-glasses, it is said, were those in which powdered egg-shells well dried in the oven were used instead of sand, such powder being less affected by changes in the atmosphere than sand would be. Sand-glasses are now seldom used except on board ship, and by domestics to compute the time for the boiling of eggs.
King Alfred's invention for measuring time by the burning of candles, which were marked by circular lines to show the progress of the hours, was another effort of rude skill, which however could have been but partially successful even in the opinion of its inventor, for the accuracy of candle-horologes is interfered with by many different influences, prominent among which must of course have been the varying qualities of the materials used in their manufacture, and the more or less care with which they were guarded from the wind, so as to prevent their guttering.
We now come to consider the date of the next grand step in the progress of Horology,--namely, that of the invention of the _clock_. The name itself may be derived either from the French, _la cloche_, a bell, or from the German, _die gloke_, or _die kloke_. There is no doubt that the word _cloche_ was meant to distinguish the instrument which marked the hours by sounding a bell, from the _montre_ or watch, which (derived from the Latin _monstro_, to show) merely shows the time by its hands. In ancient books the word _cloche_ simply stands for a bell,--the monks being accustomed to ring a bell at certain periods marked for them by their sun-dials or hour-glasses, and 'What's o'clock?' in old writers is often merely equivalent to the inquiry, 'What hour was last struck by bell?' The word horologe or hour-measurer of course equally applied to the sun-dial, the clepsydra, and the clock, and this convertibility of terms makes it all the more difficult to trace the point at which the newer invention began. Beckmann, in an ingenious analysis of various statements as to the first inventors of clocks made to go by weights and wheels, ascribes the invention to the eleventh century, but he does not attempt to name the first clockmaker. His authority for the date is the life of William Abbot of Hirshan, wherein there is mention made of a machine used by the monks for measuring time, which cannot in Beckmann's opinion have been a clepsydra. Beckmann does not believe that clocks were of European origin, but that they were derived from the Saracens. He founds his opinion upon a horologe described by Trithenius which was presented by the Sultan of Egypt in 1232, to the Emperor Frederic II. of Germany. 'In the same year,' says he, 'the Saladin of Egypt sent by his ambassadors, as a gift to Frederic II., a valuable machine of wonderful construction, worth more than 5000 ducats. For it appeared to resemble internally a celestial globe in which figures of the sun, moon, and other planets, formed with the greatest skill, moved, being impelled by weights and wheels, so that performing their course in certain and fixed intervals, they pointed out the hour, night and day, with infallible certainty; also the twelve signs of the Zodiac with appropriate characters, moved with the firmament, contained within themselves the course of the planet.'
To whom the high honour belongs of inventing the clock is, to use a not unknown phrase, 'lost in the mists of antiquity.' All the ancients who were reported as skilful in mechanics seem to have obtained a modicum of credit as clock-inventors. Archimedes and Posidonius before, the Christian era, Boëthius in the 5th century, Pacificus about the middle of the 9th, Gerbert at the end of the 10th, Wallingford near the beginning of the 14th, and Dondi at the end of the 14th, have each in their turn been asserted to be the inventors of the clock.
The sphere of Archimedes, made 200 B.C., as mentioned by Claudian, was evidently an instrument with a maintaining power but without a regulator, and therefore would not measure time in any other manner than as a planetarium, turned by a handle, measures, or rather exhibits, the respective velocities of the heavenly bodies; and the same may be said of the sphere of Posidonius, as mentioned by Cicero ('De naturâ Deorum'). The clock of Boëthius was a clepsydra, as was also that of Pacificus, according to some, for Bailly in his History of Modern Astronomy asserts that Pacificus was the inventor of a clock going by means of a weight and a balance, and if so the invention must be ascribed to Pacificus; but Bailly gives no authority for his assertion. Gerbert's horologe is said to have been merely a sun-dial, and Wallingford's horologe, called the Albion, must have as much resembled a planetarium as a clock, for the motions of all the heavenly bodies appear to have been conducted by the maintaining power, whatever that was, without controlling mechanism. This instrument, made in 1326, is also described as having shown the ebb and flow of the sea, the hours, and the minutes.
There are, however, still earlier data as to clocks in England than this of Wallingford's, for we find that in 1288 a stone clock-tower was erected opposite Westminster Hall with a clock which cost 800 marks, the proceeds of a fine imposed upon Ralph de Hengham, Chief Justice of the Queen's Bench. The tower mentioned was still standing in 1715, and in it was a clock which struck the great bell known as Tom of Westminster so as to be heard by the people in all the law courts. In Queen Elizabeth's time the clock was changed for a dial upon the clock tower, which, however, bore upon its face the same Virgilian motto, 'Discite justitiam moniti,'--referring to the fine inflicted upon the Chief Justice for making an alteration in a record by which a poor dependent was made to pay 13_s._ 4_d._ instead of 6_s_. 8_d_. A dial with this motto was still to be seen in Palace Yard, Westminster, within the last dozen years, but was removed with the houses which were then demolished to make way for the gilded palings which have since been erected between Palace Yard and Bridge Street, Westminster.
In 1292 a clock was placed in Canterbury Cathedral, which, according to a statement in a Cottonian MS., cost £30, a large sum at that time.
Dante, who died in 1321, aged 57, makes the earliest mention of an _orologio_ which struck the hour:
'Indi come orologio che _ne chiami_ Nel hora che la sposa, d'Idio surge Amattinar lo sposo, perche l'ami.'
_Il Paradiso._--C.X.
In 1344 James Dondi constructed at Padua, by the command of Hubert, prince of Carrara, a clock similar to Wallingford's, and thus obtained for himself the title of _Horologius_; which, it is said, is still borne by his descendants in Florence. In 1364 Henry de Wyck, a German, made a clock for Charles V. of France, which was erected in the tower of his palace. This clock was regulated by a balance, the teeth of the crown-wheel acted upon two small levers called pallets which projected from, and formed part of, an upright spindle or staff, on which was fixed the balance, and the clock was regulated by shifting the weights placed at each end of the balance.
In 1368 Edward granted protection against 'injuriam, molestiam, violentiam, damnum, aut gravamen' to three Dutch horologers, John and William Uneman and John Lietuyt, who had been invited to this country from Delft.
Chaucer, who died in 1400, speaks of a cock crowing with such regularity as to rival a clock:
'Full sikerer (surer) was his crowing in his loge As is a clok, or any abbey orloge.'
Whether the abbey horologe referred to was really a clock in our sense of the term, or merely the bell rung by the monks at a certain hour indicated by the clepsydra, is matter of conjecture, but the probability is, that clockmaking had advanced sufficiently about this time to have given rise to Chaucer's simile. Froissart speaks of a famous clock which struck the hours, and was remarkable for its mechanism, and which was removed in 1332 by Philip the Hardy, duke of Burgundy, from Courtrai to his capital at Dijon.
After this date frequent mention is made of clocks in various histories, some of which instruments remain even to the present day. Dr Heylin thus describes a famous clock and dial in the Cathedral of Lunden in Denmark. 'In the dial are to be seen distinctly the year, month, week, day, and every hour of the day throughout the year, with the feasts, both those which are movable and fixed, together with the motions of the sun and moon, and their passage through each degree of the zodiac. Then for the clock, it is so framed by artificial engines that whensoever it is to strike, two horsemen encounter one another, giving as many blows apiece as the bell sounds hours, and on the opening of a door there appeareth a theatre, the Virgin Mary on a throne with Christ in her arms, and the three kings or Magi (with their several trains) marching in order, doing humble reverence, and presenting severally their gifts,--two trumpeters sounding all the while, to adorn the pomp of the procession.'
The clock at Hampton Court is one of the most ancient in England, but all that remains of the original structure is the dial and work connected with it, facing the east, in the second court of the old part of the building erected by Wolsey. Of the ancient body or works there is no record, and its maker is unknown, but it bears the initials N.O. and the date 1540.
There is a celebrated antique clock at Strasburg which is described as striking the quarter-hours by four figures, symbols of the ages of man;--the first being struck by a child with an apple, the second by a youth with an arrow, the third by a man with a staff, and the fourth by an old man with a crutch, then came Death, who struck the hour, and thus reminded the observer that his last hour would eventually arrive.
From the evidence adduced respecting the origin and inventors of the clock it is not unreasonable to conclude with Ferdinand Berthoud (a Frenchman who wrote much and was a great authority upon the subject) that such a clock as that which was constructed by Henry de Wyck for Charles the Wise of France, was not the invention of one man, but was the result of a series of inventions made at different times by various persons, each of which is worthy to be considered a separate invention. It was the simple employment of the natural force of gravity as to the fall of bodies in free space, that paved the way to the extreme accuracy and constancy of rate which belong to the clocks of modern times, and the conclusion to which Mons. Berthoud arrived respecting the progression of the essential improvements is thus stated:--
1. Toothed wheel-work was known in ancient times, and particularly to Archimedes, whose instrument was provided with a maintaining power, but had no regulator or controlling mechanism.
2. The weight applied as a maintainer at first had a fly, most probably similar to that of a kitchen-jack.
3. The ratchet-wheel and click for winding up the weight, without detaching the teeth of the great wheel.
4. The regulation of the fly depending upon the state of the air, it was abandoned, and a balance substituted.
5. An escapement next became indispensable, as constituting with the balance a more regular check than a fly upon the tendency which a falling weight has to accelerate its velocity.
6. The application of a dial-plate and hand to indicate the hours was a consequence of the regularity introduced into the going part.
7. The striking portion, to proclaim at a distance, without the aid of a watcher, the hour that was indicated: and this was followed by the alarum.
8. The reduction and accommodation of all this bulky machinery to a portable and compact size, as in watches.
Such a succession of ingenious contrivances, introduced by different men to improve upon the first rude instrument, is perfectly analogous to the successive improvements which have been made in the modern clock, since that of Henry de Wyck's was constructed. Large iron wheels, continually exposed to the oxidizing influence of the air, in which unequal and ill-shapen teeth were cut with the inaccuracy of a manual operation, were by no means calculated to transmit the maintaining power with perfect regularity to the balance, supposing it to have been a good regulator; but when it is further remembered that the alternate direct pushes of the escape-wheel against the pallets must have produced jerks, and destroyed, or greatly disturbed, the regularity of this most essential part of the mechanism, great accuracy was not to be expected; even minutes were deemed too small portions of time to be shown by such a machine. The clock was set daily by some person specially appointed to the office, and even then was not to be depended upon, for forty minutes' variation in twenty-four hours was not thought to be an ill performance.
The most ancient clocks had no pendulum such as we now see, but had instead a balance vibrating on the top of the clock, as seen in illustration, p. 108, which is an example of ancient clockwork.
Upon the invention of springs, in lieu of weights, as the maintaining or motive power in clocks, which was made towards the close of the fifteenth century, it became obvious that time-pieces might be rendered portable, and that the new motive power, a coiled spring, could act independently of position. This discovery was of great importance, and yet to whom we are indebted for it is unknown; the value of the invention became still more apparent when the fusee, or mechanism for equalizing the variable power of a coiled spring, was applied. Berthoud says, 'It was soon perceived that the action of the spring being much greater at the height of its tension than at the end, great variations in the watch resulted therefrom. This was remedied by a mechanism called _stack-freed_, that is, a kind of curve, by means of which the great spring of the barrel acted on a straight spring, which opposed itself to its action, and when this spring was nearly down, acted more feebly.' The word _stack-freed_ was stated to be German, and therefore gave rise to a supposition that the invention was of German origin, but the word is not to be found in a German dictionary, and, if ever German, it was probably strictly technical, and soon became obsolete. Berthoud has given a drawing and description of a portable clock, probably by Jourdain, without a fusee, and some of the modern continental watch-makers have, perhaps, derived their idea from it of making a watch keep time without a fusee. Up to the close of the 15th century the motive power in clocks was always obtained by means of weights; the invention of the coiled spring rendered them portable.
Whatever be the date or origin of the watch or portable clock, certain it is that there was mention made of such an instrument as far back as 1494, by Gaspar Visconti, an Italian poet, who in a sonnet describes 'Certain small and portable clocks made with a little ingenuity, and which are continually going, showing the hours, many courses of the planets, the festivals, and striking when the time requires it.' The sonnet is, as it were, composed by a person in love, who compares himself to one of these clocks. One of the earliest places of watch manufacture was Nuremberg, and foremost among its horologers was Peter Hele, who was thus described by Doppelmayer in his 'History of the Mathematicians and Artists of Nuremberg.'