Time and Time-Tellers :: TURRET CLOCKS.

TURRET CLOCKS.

A Church tower without a clock and bells seems an unfurnished edifice, which must be fitted and filled before it can serve the purpose for which it was built;—like a form without life, a body without a soul. A good Church clock is useful to everybody; it is the friendly monitor alike of rich and poor,—the regulator of every private time-piece,—the standard of time for a whole parish or township. By it the artisan or mechanic trudges off to his daily labour; by it the tradesman opens and closes his shop; by it the schoolboy is admonished as 'with shining morning face he creeps like snail unwillingly to school;' by it the law itself regulates its penalties,—(enacting, as it does, house-breaking between nine at night and six in the morning to be the heavier crime of burglary;)—by it, in a word, are all the multifarious transactions of everyday life more or less regulated and measured, and when the church clock stops, it produces a social discomfort and anarchy throughout a whole neighbourhood, to an extent scarcely credible. A good public clock is a benefit to all,—a faulty one is a general nuisance and a continual source of irritation. A public clock is in its way as necessary as the public highway, the public market, the public law itself. It is the product and the symbol of advanced civilization, the one everwakeful watchman and trusty friend of all, by whose chimes the sleepless merchant has often planned his ventures or sighed o'er apprehended losses and dangers; the student busied with researches has consumed the midnight oil; the sick have counted their hours of pain, longing in the night for the dawn, in the daytime for the night. On the other hand, when one like Mr Justice Shallow is reminded of the mad days of his London youth, he very aptly associates them with the Bacchanalian memories which Falstaff appeals to,—'We have heard the chimes at midnight.'

To have lived 'where bells have knoll'd to church' was according to Shakspeare to have been blessed by humanizing influences comparable with those produced by having—

'Sat at good men's feasts, and wiped our eyes Of drops that sacred pity has engendered.'

Cowper can find no better words to describe the utter desolation of the island where the shipwrecked Selkirk bemoaned his absolute solitude 'out of humanity's reach,' than by putting into his mouth the language—

'But the sound of a church-going bell These valleys and rocks never heard, Never sigh'd at the sound of a knell, Nor smiled when a Sabbath appear'd.'

In our everyday experience we can each testify to the truthfulness of the poet who points to the close association which exists in most minds between the church clock and the varying times and seasons, with their different joys and sorrows, and we can most of us say, with Southey,—

'I love the bell that calls the poor to pray, Chiming from village church its cheerful sound, When the sun smiles on labour's holy-day And all the rustic train are gather'd round, Each deftly dizen'd in his Sunday's best, And pleased to hail the day of piety and rest. And when, dim shadowing o'er the face of day, The mantling mists of eventide rise slow, As through the forest gloom I wend my way, The minster curfew's sullen voice I know, And pause, and love its solemn toll to hear, As made by distance soft it dies upon the ear.'

It is but a short step from the sentimental consideration of such reminiscences to the practical inquiry how is the public time kept, and yet it is one which probably is seldom taken with a view to more or less thorough investigation. Without traversing the distance which divides us from that antique time when Archimedes measured the shadows of the Pyramids by his walking-stick, or when the 'dial of Ahaz' was constructed as one of the first of historical time-measurers, we can discover the principles upon which an instrument such as a thoroughly serviceable public clock of the present time, with all the newest improvements both in time-keeping and in wearing qualities, should be produced.

It is of some consequence, in the first place, to know that the introduction of steam-machinery has added to the accuracy of clockwork and at the same time considerably diminished its cost; fifty or sixty years ago there would have been charged as much as £800 for a turret clock inferior to that which may now be procured for £150; and the result is to be seen in the largely increased numbers of public time-pieces. It is obvious, however, that there is none the less need of care in the choice of a Clockmaker, for upon his skill and trustworthiness will depend whether the money be well spent or not, and whether the instrument furnished by him prove to be valuable and serviceable. It is not a purchase wherein the buyer can usually of himself judge of the merits of his bargain, he must rely upon the reputation established by previous works of the same kind. If the Clockmaker be not merely a clock-seller (as is too often the case, for Turret Clockmakers are but few), he will be able to point to similar instruments made and set up by himself in different towns and cities, in proof of his ability, but there will still be a necessity for explaining to the purchaser the chief points upon which the accuracy of such a time-keeper must depend.

In the first place, it is necessary to say that Turret Clocks are not merely house clocks upon an enlarged scale, differing from the latter merely in size and weight, but that the extra strength of the machinery requires greater weight of materials 'in a ratio as much higher as the cube is higher than the square of any of its dimensions,' and that increased weight means increase of friction. Besides this point which is peculiarly the province of the Turret Clockmaker, there are important questions to be considered by architects and their employers as to the proper method of constructing a Turret Clock chamber, so as to prevent too much atmospheric variation,—heat and cold, wind and damp, being each likely in some degree, as the seasons change, to affect the public time-keeper,—as witness the clock of St Paul's Cathedral, popularly believed to be an exemplary piece of mechanism, and yet often forced by the wind to vary its time so as to damage its own reputation among those who narrowly watch its behaviour under what may be called trying circumstances. It is not wise to build a tower without careful consideration for the tenant which is to occupy it, or having regard merely to architectural notions of external proportion, for usually it happens that when clock and bells occur as an afterthought, there is often some difficulty and extra expense in planning the room for them. Plenty of length and breadth to allow of the proper fall of the clock-weights and the swing of the pendulum save much in the cost of fixing, and are necessary to secure good time-keeping with the least trouble, for it is obvious that where numerous bevelled wheels with rod-work are employed for the purpose of moving the hands over the dial, if the probabilities of unvarying accuracy are not lessened, the cost must be much increased. Works which have to be placed at some distance from the dials must be more powerful than if they could be put in their proper place, and a little forethought in the architect will save much money both in the original price of the machinery of a clock and in its subsequent repair. Then again, there is always the question for and against the illumination of dials to be considered, and of course with this is unavoidably mixed up not only the arrangements as regards space for the proper working of the time-keeping, striking, and lighting machinery, but the vexed question of ventilation above referred to,—some horologers asserting that chambers as nearly air tight as may be should be devised, and others that there ought to be a draught through the clock-room. There are in fact so many opinions more or less excellent, according to the circumstances of each case, that there is no laying down any arbitrary and unvarying rule,much must be left to the discretion of the Turret Clock manufacturer,—upon whom as has been already stated it is necessary also to rely for the essentials of a good clock, viz., the soundness of the materials, the quality of the workmanship, and the scientific accuracy with which the instrument has been planned and put together. Now before considering the present advanced state of the art of Turret Clockmaking and the various improvements which have to be carefully studied and applied by the makers who would bear the highest reputations as manufacturers, it will be necessary to bear in mind what has been said of the step-by-step progress in horological science of which we have already endeavoured to give the chief particulars. From 1288 A.D., the date of the oldest historical clock—that mentioned as having been set up near Westminster Hall by means of funds derived from a fine levied by the Lord Chief Justice of the period—till now when Big Ben reigns in its stead, is a long interval, with many wonderful incidents, and some great historical names. Henry de Wyck's Paris invention, Galileo's discovery of the pendulum, Huygens's practical application of that discovery, Dr Hooke's 'anchor' escapement, and Graham's dead-beat escapement, Harrison's 'gridiron' pendulum, and the latest applications of electricity and eccentricity, have each and all their peculiar attraction for horological students, but we need not recur to these branches of this highly interesting subject elsewhere treated of. We will proceed to mention a few memoranda about several old public clocks whose ingenious mechanism gained for them a well-deserved fame,—not, perhaps, so much for accuracy in time-keeping as for the grotesque devices with which old clockmakers amused their contemporaries? To them time, as such, was perhaps of not so much consequence as it is to us in these days of telegraph and steam communication. We moderns seem to think it a task sufficiently difficult to set up a sound public time-piece without connecting therewith the wonder-working machinery of a wax-work exhibition.

The Clock at Wells Cathedral, made originally A.D. 1340, by a monk named Peter Lightfoot, is one of the best known of its class still in some sort of working order. The dial of this horologe is divided into 24 hours; it shows the motion of the sun and moon, and bears upon its summit eight armed knights on horseback, tilting with lance in rest at one another, by a double rotatory motion. This clock was removed from Glastonbury to Wells after the dissolution of the Glastonbury Monastery. In 1835 the works were so worn away that they were replaced by a new train, the curious old dial and equestrian knights being still retained.

St Dunstan's Clock [see p. 137]. This Clock, when old St Dunstan's Church in Fleet Street was

Wells Cathedral Clock.

pulled down, was sold by public auction, and bought by the late Marquis of Hertford, for whom Decimus Burton the architect erected St Dunstan's Villa in the Regent's Park. In the grounds of that villa this old clock with its automaton giants striking the hours and quarters was put up, and it is there still, to be seen in full working order, performing the same duties as of yore in Fleet Street.

St James's Palace Clock [see p. 138] is one of the most ancient public time-pieces now in use, but is intended soon to be removed it is said to South Kensington Museum. It has a locking-plate with ting-tang quarter, the quarter hammers being raised from the pin wheel while the striking hammer is lifted from the pins in the main wheel. It has a crown-wheel escapement with teeth on its edge, and the pallets working upright instead of over the top like a verge escapement. The hands are connected by the bevel wheels below the clock. The whole of the going train with the intermediate and bevel wheels are attached to the one bar so that the whole of the works have to be removed if one piece requires alteration or renewal. The pendulum rod is of iron.

St Paul's Cathedral Clock [see p. 140] is one of the best examples of old-fashioned clocks in London; it occupies the clock-room in the south-western tower. It may be described as a ting-tang quarter on the rack principle, having hammers raised from pins in

St Dunstan's Clock.

the main wheel as in St James's Palace Clock. The train is run in a bar, so that to get away one piece the rest must be disturbed. The escapement is a

St James's Palace Clock.

recoil, beating two seconds with a wood rod pendulum. The length of the minute hand is eight feet, and its weight 75lb; the length of the hour hand is five feet five inches, and its weight 44lb. The diameter of the bell, made from old 'Great Tom of Westminster,' is about 10 feet, its weight 11,474lb; the hammer weighs 145lb, and the clapper 180lb.

The Old Clock at the Royal Free Hospital, Gray's Inn Lane, is a fair specimen of the work of 120 years ago. It has a recoil escapement, most of the wheels are of wrought-iron, cut by hand, as is also the pinion. The pendulum rod is of iron with leaden bob.

THE WHEELS.

And now, in order to form a judgment of what is necessary to be done to make a really sound and valuable Turret Clock of the present day, let me describe the materials of which it should be formed. One of the most important parts of a clock is the wheel-work. Iron wheels are of course very much cheaper than those which are made of gun metal or hard brass, but iron wheels, however well they may sometimes wear, are more liable to oxidize and to decay, and although it is certain that a large number of clocks are constructed with iron wheels by London houses of some reputation, a few years are generally sufficient to prove

St Paul's Cathedral Clock.

Old Clock at the Royal Free Hospital.

such time-pieces to be very faulty, and to necessitate the substitution of wheels of the superior metal.

The best clocks are usually made with wheels of the best gun metal. The teeth are cut by steam power, with an improved cutting engine; and at the same moment that the teeth are cut, they are finished by the engine without the aid of the file, sand-paper, or other polishing materials, so that the most minute difference cannot possibly occur, their accuracy being secured even to the thousandth part of an inch. In the old times this work was done by a man turning a fly-wheel, but that method necessarily occasioned an unevenness of cut which had afterwards to be removed by filing and hand polishing. Wheels thus made could not of course have that precision of movement which is essential in a public clock, and which can only be obtained by a perfect mechanical fit of the teeth of the wheels, such true mechanical fitting being only secured by truly accurate cutting machines. Hand cutting varies with each artisan, and therefore cannot be equally trustworthy. In cheap clocks, constructed to suit public companies who give their contract to the lowest tender, iron is frequently used instead of steel, both in the pinions and arbors, and cast-iron takes the place of gun metal or hard brass in the wheels and bosses,—the result usually being that the Public Clock gets into disrepute through its requiring to be repaired so frequently, and more money is expended upon such repairs than would have sufficed for the purchase of a thoroughly perfect time-keeper. It is urged by the advocates of iron wheels that a clock can be manufactured at a considerably less cost by their employment, but in estimating expense there seems to have been overlooked the important question, as to what will be the probable durability of the machine.

I should be sorry to condemn wholesale all clocks, the main wheels of which are made of iron, but very certain it is that a large proportion of clocks constructed of this material and by London houses of great reputation (despite of their possessing an escapement invented by amateurs who consider themselves the depositories of all horological knowledge), have been found most faulty time-keepers, and after a few years have become entirely worn out and useless.

It is argued (and rightly so) by the advocates of iron wheels that case-hardened pinions should not be used, in consequence of their wearing with great unevenness, but such persons should be reminded that this objection is much greater in the instance of cast-iron wheels. A case came under my notice some time since of a clock made by a London house, with iron wheels, which after comparatively little time became entirely worn out and had to be removed, a result not at all surprising to those who are aware of the porous nature of iron. The Teeth of wheels have to be made with the greatest skill and care in order that the entire mechanism shall work without friction, and shall not only temporarily keep time with regularity, but shall last for many years without renewal. Teeth should fit into one another without a squeezing pressure (which is equivalent to friction), but with exact uniformity of contact, the action being almost entirely between the teeth separating from each other and not between those which are approaching, i.e. in technical language, the action should be after the line of centres of the wheels and not before it.

Church clocks were accustomed formerly to be made to go for thirty-four hours, and to be wound up every day; by the frequency of which winding the clock could be made to keep time with great accuracy, for regulating could be attended to as frequently, and no great variation could well occur in twenty-four hours. But the regulating, as a matter of course, requires a regulator, or standard, of time, which is not always to be found in country places, nor even is the man in charge of clock-winding always in possession of a watch sufficiently accurate to convey the time from the regulator if there were one to the Church clock. Of late, Church clocks are made to go eight days, and so the labour of frequent winding has been saved, while at the same time by extra care in the manufacture and fixing of a clock, there need be no necessity for frequently regulating it.

PENDULUMS.

Whether the credit of practically applying the mathematical theory and properties of the pendulum was or was not due to Huygens the Dutchman, we have seen that Harris, a London clockmaker, put up the first pendulum clock in St Paul's Church, Covent Garden, in 1621. The great advance upon this discovery was that the pendulum bob must move not in a circle but a cycloid; and that back and front should be alike both in weight and shape to secure regular vibration. Cylindrical bobs are now in general use for large clocks. The old iron rod pendulums were soon discovered to be affected considerably by variations of heat and cold,—the difference between winter and summer being ascertained to amount to the loss of a minute a week. Harrison's gridiron pendulum was one of the chief endeavours to prevent such variation, followed after a long interval by other ingenious inventions, which gained temporary approval and gradually fell into disuse. Room should be provided by the architect of every clock-tower in the chamber below that containing the movement, to allow of the swing of a 15-foot pendulum.

FALL OF THE WEIGHTS.

We have seen that the position in which a clock is placed in regard to the dial or dials whose hands it is to drive is a matter requiring some attention. Properly the floor of the clock-chamber should be so planned that the clock might stand immediately behind, and level with the dials; for there is extra expense and inconvenience connected with any more distant situation of the works,—the fall of the weights being sometimes difficult in such case to be provided for. The weights should hang, wherever it is possible so to arrange, immediately from the barrel to which they are affixed, without the intervention of pulleys of any kind, and much expense may be saved by providing for the descent of the weights to a considerable depth below the clock-chamber. As an instance however of the extent to which such difficulties can be overcome, I may mention that the hands of my great clock at the International Exhibition were situated nearly 400 feet from the clockworks, while the weights were carried by iron wire ropes over pulleys below the floor to a distance of 200 feet from the movement, then over another pulley fixed at a height of 80 feet from the ground.

The Escapement is perhaps the most important part of a clock.

CROWN-WHEEL ESCAPEMENT.

This is the earliest known escapement, and is to be found, as we have said, in Henry de Wyck's clock, all the difference between his escapement and the above being that one of the weights in de Wyck's balance is now set in a vertical instead of a horizontal plane. The bent end or fork seen in the illustration connects the pendulum with that arm technically called the crutch.

THE ANCHOR ESCAPEMENT.

After the crown-wheel escapement, the anchor escapement, invented by Dr Hooke or one of his contemporaries, came into general use, and remains so still; but it is not generally applied to those clocks which are required to go with the nicest accuracy.

In the next illustration the tooth is seen escaping from the left pallet at the moment of the right pallet's infringing upon the opposite tooth, the pendulum is therefore to be seen still rising a little to the left, and will thus cause the wheel to recoil a little; upon its return the pallet and pendulum are again urged to the right, and so the impulse is continued which is necessary to maintain the motion.

THE DEAD-BEAT ESCAPEMENT.

invented by Graham is the one in most general use for the best clocks made by London makers of the highest repute.

FRENCH SINGLE-PIN ESCAPEMENT.

This is a simple and ingenious escapement (see next page), which after being used for some time in both France and England went out of use, when, but recently, it was re-invented by a London watch-maker. The teeth are pins of steel set in the face of the wheel, and the upper half of each cylinder cut off as well as a small portion of the under or acting side. This escapement has one great advantage—that if a pin becomes worn or injured it is easily replaced, whereas in a wheel, if one tooth is damaged the wheel itself is worthless.

THREE-LEGG'D GRAVITY ESCAPEMENT.

The above illustration represents a regulator escapement as it would appear in a front view; the pallets are lifted by the three central pins. The locking teeth vary in size from one to nearly two inches. The horizontal pieces projecting from the top of the pallets form the adjustment for the arc of the pendulum.

The great advantages possessed by this escapement over all other gravity escapements, &c., are as follows:—

1. It requires no oil.

2. The angle of the detent planes reduces the friction to almost nil.

3. As the impulse and the unlocking are in one direction, the escapement is unlocked without recoil of impulse arms.

4. No impending force to the pendulum from inertia of impulse arms.

5. The hold in the stops can be increased or diminished to any practical extent by reason of the inverted impulse arms.

6. Less affected by any disturbing forces of the train in proportion to the pressure on the stops.

7. Will bear more weight and give more power to the train without increasing the arc of oscillation.

8. No possibility of tripping under any increase of motive power.

9. The minimum arc of vibration to unlock is 8-tenths of a degree. Other escapements of similar construction require from 4° to 7°.

10. Take less weight for the motive power in proportion to the difference of pressure and draught on the lockings.

11. Unlocks by gravitation instead of by the pendulum and at the time of impulse.

12. Requires no fly nor remontoir, and thus reduces the weight of the motive power by one half.

13. The impulse giving motion to the pendulum increases as the force of gravity on the pendulum decreases. A great advantage over those escapements in which the unlocking is done by the pendulum when its momentum is nearly expended and at the extremity of its arc of vibration.

14. The angle of the detent planes can be set so as not only to offer no resistance to the unlocking, but to give an actual impulse in the same manner as the impulse pallets of a dead escapement. This completely frees the impulse which gives motion to the pendulum from any retarding influence of the train.

15. The arc of vibration is more equal in this than in any other gravity escapement.

16. It is not so liable to stop in consequence of a diminution of arc from the variation of motive force in train.

17. It will answer for regulators as well as for turret clocks, its arc of vibration being from 1° to 3°.

DOUBLE THREE-LEGG'D ESCAPEMENT.

This escapement is chiefly designed for turret clocks with heavy dial-work requiring much power on the scape-wheel. The peculiarity consists of two locking wheels with one set of lifting pins between them. The wheels are set so that the pallets may lie between, and the pallets fall with the pendulum clear of all other contact. The pallet D for instance has its stop in front for the wheel A B C to act upon, and the E stop is acted upon only by a b c, the E and A being on different planes. In this escapement, by making the teeth longer and the pallets shorter, the resistance of the pendulum is much reduced, and the stride of the pallets being wider, the actual weight required of them is considerably lessened,—a point of some importance.

THE REMONTOIRE.

is an invention which, being derived from the French, still bears its French title, and consists of either a train remontoire, or a gravity or remontoire escapement, in which latter the impulse is not given to the pendulum directly by the clock-train or weight, but by some small weight lifted up or a small spring bent up by the clock-train at every beat of the pendulum, so as to secure a uniform and constant impulse, the remontoire weights being lifted either faster or slower according to need. The train remontoire differs from the escapement but slightly, the chief difference being that the small weight or spring which gives the impulse to the pendulum is not wound up at every beat, but at some larger interval, seldom more than half a minute. Its effect is to counteract the various errors to which large clocks driving heavy hands are always liable, and to diminish the friction which arises from the use of heavy weights—these being in very large clocks almost incredibly heavy; for instance, the weights used by me for my clock in the Great International Exhibition of 1862 amounted to more than two tons. Whatever the cause of inequality of movement in the clock, whether it be dust or dirt, or insufficient oil, or whether it be wind delaying or expediting the progress of the hands on the dial, the remontoire regulates and counteracts.

THE DIALS.

The utility of a Public Clock is considerably enhanced by its being provided with a dial marking the time in the simplest and most unmistakeable lines, so that it may readily be ascertained at any reasonable distance from the clock-tower what is the hour either by day or night. In order that this important requisite may be attained, it is of course necessary that the dial shall be so constructed as to be visible both by night and day, and so arises the necessity for providing illuminating power either from within or from without. Now the simplest method, and perhaps also in the end the least objectionable, is that followed at the Horse Guards, where the dial forms part of the tower itself, and is lighted not from within, but from without. The advantage of this arrangement is, that the architect can make the dial harmonize with the character of the building, that the illuminating power is kept apart from the clock, and if the centre of the dial be slightly sunk the hands may be brought quite close to the face, so as to prevent any seeming error in time, as is sometimes caused by the convexity of a copper dial. The figures too, having been once carefully divided and cut into the stone, are renewed, so to speak, by merely being painted over.

Memorial Turret Clock Dial.

Dials may be made of any material, wood, stone, slate, iron, brass, copper, and coloured or semi-opaque glass. Copper dials possess many advantages, and these have been of late years preferred, except where more ornamental dials are required, in which case slate and skeleton frames are used with good effect. The large dial of my great clock which was placed over the principal entrance of the International Exhibition Building in the Cromwell Road was of slate, elaborately enamelled with white and gold on a blue ground. Another kind of dial having a good effect is that erected by myself some time since for Sir Moses Montefiore, at the Synagogue, Ramsgate, consisting of a skeleton or framework of iron fitted with Minton or encaustic tiles. A dial such as this can thus be made with comparatively little expense during the erection of the tower, and the architect can then, as I have said, design it so as to be in keeping with the edifice; the Minton tiles have also the advantage of being almost indestructible, and of being made of any pattern or colour. The chief points to remember are that the dials should be slightly sunk in the centre so as to allow the hour hand to traverse in the sinking point close to the disc and the figures, and especially that the dial should be made large enough to distinctly show the hour. Properly the dial should never be less in diameter than one-tenth of the number of feet which it is distant from the ground, and in all cases where it is possible I should recommend it to be much larger than this. The dials of St Paul's and Westminster are larger than they would be under the above rule, and they are certainly not too large. As to the colour of the dials, figures, and hands, there is not much choice; dark ground and gilt figures, or white ground with black figures, or a skeleton frame with gilt figures are the chief in use. In the white semi-transparent dials with opaque figures used for illuminated clocks, the time, which is seen with sufficient distinctness by night when the light is behind the figures, is not as clearly indicated by day. To remedy this defect an invention has been applied by which the dial when illuminated at night throws out a beautiful transparent light admirably marking the position of the figures and hands, which being black or dark blue, or even strongly gilt, can also be distinctly seen by day, even as clearly as the long-approved copper dials painted black with gilt figures.

THE HANDS

should be most carefully made, and like the figures should be painted of a colour which shall most powerfully contrast with that of the dial. The hands are almost invariably made of copper strengthened by diaphragms, and poised from the inside. In some old-fashioned clocks in which the hands have been poised from the outside the effect has been produced of a third hand, and numerous mistakes caused thereby. As to the shape of the hands, there is but one simple rule, namely, that the less of ornamentation in them the better. The minute hand should be perfectly plain, with a tapering but not too fine point, extending to the top of the figures; the hour hand should be of equal breadth and plainness, but its point should be more marked by perhaps an arrowhead or heart-shaped tip only reaching to the bottom of the figures. With large hands counterpoises are found necessary, and these should be placed inside the dial if possible, for they are when outside sometimes mistaken for the point of the hour hand. If a counterpoise must be placed outside, it is better to arrange that it shall be as little as possible, and that the inside counterpoise make up the difference, giving to the latter perhaps two thirds, and one third to the former,—but in any case care has to be taken to prevent the counterpoise appearing like a hand.

THE FRAME.

The old-fashioned clock-frame, known in the trade as the 'bedstead,' is now generally superseded by the horizontal frame originally introduced by the French, which possesses the special advantage of not only being durable and strong, but that it allows of any part of the clock which may have been injured, or may require cleaning, being easily taken out and replaced without interfering with other portions of the mechanism,—any wheel can be separately handled and removed. In the old upright frame which is even now still in use by some of the more ancient firms of clockmakers, if any part of the clock be injured the entire machine must be taken to pieces.

THE FIXING

of a Turret Clock requires much careful forethought and experienced labour; because whatever oversight has been made by the architect in planning the clock-room must be made good by the clockmaker who has to fix up a public time-piece. In the first place the latter will take care that the supports of the clock shall be sufficiently strong and free from vibration, and that the movement shall be bolted securely to the iron girders, or strong oak beams provided for the purpose; he will remember that when it is intended that the clock shall strike the hours and quarters, that the bell or bells should be hung as high in the tower as possible, so that when the stroke of the hammer is given by a perfect fall of the weights, the louvres of the tower should be so arranged as to bring out the full sound of the bell, as in the case of the bell at St Paul's cathedral, which, though only weighing 5 tons 4 cwts., is frequently heard on clear nights as far as Windsor. He will in a word require to be acquainted with all the points of importance attached to his rather intricate duty, or he may by failure render nugatory the best workmanship that could be bestowed in clockmaking. The wiser arrangement as to clock-fixing is to intrust the duty to the clockmaker, and he will then necessarily bear the sole responsibility of any mistake.

The Winding and keeping in order is, as we have said, a less laborious task as respects modern clocks than those which were made fifty years ago, inasmuch as, although it is the duty of a clock-winder to watch daily the action of the time-piece under his charge, he need not perform his winding duties oftener than once a week. He must be on the alert to observe any effect produced by the action of the wind or the fall of snow upon the hands of the clock, which under certain conditions is not uncommon; he must note by some good regulator any tendency to variation in the Church clock, and he must also observe the Equation of Time, which is the difference between true and mean solar time for each day, and which is not quite the same for every year, because it moves on about a quarter of a day in each year until leap year comes and puts it back again. The Equation may be reckoned by an Equation Table, or by the time mentioned in the Almanacs as 'clock before' or 'clock after sun.' It is obviously a very important requisite for good time-keeping that good horological instruments shall be intrusted to skilful and careful hands. In many instances it has happened that escapements made upon the truest scientific principles, and set going in thorough working order, have been so injured by the mechanical genius of the village (some blundering sexton, or some jack-of-all-trades, whose education in mechanism must be exercised at the parish expense), that the new clock with all its merits has been seriously damaged. In such a case the clockmaker had better be at once consulted.

A MODERN TURRET CLOCK DESCRIBED.

The Turret Clock which the highest skill and the best experience of the value of the latest improvements can produce, may be thus described:—

The Bed or Frame is of cast-iron. The Barrel on which the cords are wound possesses a metal cap in front, and a ratchet or toothed wheel at the back end; between this cap and ratchet is a metal drum or tube adapted to the width of the Frame. Passing through the drum is an axle or barrel-arbor, on the back end of which the main or barrel-wheel is fitted

A Modern Turret Clock.

so as to allow the line which carries the weight to be wound upon the barrel without moving the wheel, which latter is kept in place by means of a cap or key pinned tight on the arbor. Upon the barrel wheels are fitted clicks and springs, the former falling into the toothed wheel or ratchet, and the latter keeping the clicks in place while the clock is being wound up, for as the weights are wound up the clicks prevent the barrel running back. At each end of the barrel arbor is a pivot in brass bearings fitted in plumber block, and bolted on the bed or frame with bolts and washers. Beyond the pivot on the front of the arbor is a square to receive the winder. The uprights or small frames for carrying the going-train contain the following; first, there is an arbor across the frame at the back of which is a pinion working in the teeth of the barrel-wheel; at the other end of the arbor is the centre-wheel with teeth cut in it, and above this wheel is another pinion running into it with a wheel at the other end, termed the third wheel and pinion. The escape-pinion runs into the third wheel; on this arbor is fitted the escape-wheel, which has very fine teeth cut in it. Above the escape-wheel is an arbor termed the verge arbor, to which are fitted the pallet arms. The pallet bits or pads working in the escape-wheel teeth are of hardened steel polished. At the back end of the verge arbor is fitted the crutch which connects the escapement and the pendulum rod. The

Hour-Wheel and Snail.

escapement is that called the dead-beat or lever escapement, found to be the best for time-keeping, and least likely to get out of order. Upon the set-hand arbor, used for setting the hands on the dial to time, are two springs or keys to keep in place a wheel fitted loosely on the arbor, and working in the teeth of the centre-wheel. The hands are set by means of the set key which fits on the end of the arbor in front. At the back end of the same arbor is a joint by means of which an iron rod connects the clock to the dial, and works the outside hands. The whole of the arbors are turned with suitable pivots into brass bearings screwed into the uprights, and all bolted to the bed or frame by stout bolts and washers. On the front upright is fitted an index or set-dial by which to set the outside hands, and two wheels and pinions, termed the motion or dial-work, fitted on sockets and working on iron studs which are screwed into the upright. Upon the largest wheel, known as the hour-wheel, is fixed a snail having twelve steps in it for regulating the strokes to be given at the different hours. The striking-train consists of a barrel similar to the going-train, only that it has a camm or toothed-wheel fitted on the back of the barrel-wheel for the purpose of raising the hammer which strikes the bell, a lever being used called the hammer-tail. This barrel is fitted into bearings in plummer-block, and bolted on frame. The train of wheels and pinions fitted in arbors, and working in brass bearings, consists of,—the pallet pinion fitted tight in the pallet arbor and working in the teeth of the barrel-wheel; at the front end of this arbor is a pallet of steel working in the teeth of the rack (see next illustration), and gathering it up as the blows of the hammer striking the hours are given on the barrel. Above the pallet arbor is a pinion running into the teeth of the pallet wheel and termed the fly-pinion, as it is used for regulating the blows or strokes. Fans are attached to the fly-pinion to assist in regulating the striking,—the intervals between the strokes being thus made longer or shorter as desired. Fitted to the fly-frame is a ratchet with two clicks and springs, these being used to prevent the train being stopped too suddenly, and the damage likely to arise therefrom. At the right-hand side of the clock frame is an arbor to carry the work for the maintaining power, by means of which work the clock is kept going even while it is being wound up, and injury to the escapement is at the same time prevented. But for this maintaining power during the winding-up, whilst the pendulum is vibrating to and fro, the pallets are liable to catch the teeth of the wheel, and these are so fine as to be

The Rack.

readily injured. As properly fixed the clock cannot be wound up unless this maintaining power is put in action by means of a lever passing in front of the barrel-square, so that the winder cannot be put on the square until the lever is raised and puts this power in action. The repeating work for the striking-train is fitted on brass sockets working on wrought-iron studs screwed into the front upright, and consists of the Rack-hook, Warning, Locking, and Lifting pieces. The Rack is a portion of a circle with a number of half-circular teeth cut on its edge; at the end of the Rack is the Rack-arm fitted with a spring having a nib or pin in it, which nib or pin falls upon the steps of the before-mentioned hour-snail, and thus the different strokes are given at the hours; as the nib falls nearer the centre the rack drops a greater

Pendulum Rod.

number of teeth. The Rack-hook is placed above the rack to catch the rack as it is gathered up by the gathering pallets, and when the proper number of strokes has been given this hook falls into a deep tooth, and then, by means of a locking-piece attached to it, causes the train to be locked with the stop-piece on the fly-pinion arbor, this latter piece forming part of both the locking and warning work. The lifting-piece lifts the rack-hook out of the deep tooth in the rack and locking, by means of a snail or eccentric fitted on the set-hand arbor. On this lifting-piece is also a piece for the warning, fitted on a small stud. The pendulum rod has a brass top, and some adjusting work with a steel suspension spring set in brass, by means of which the clock can be put in beat with great exactness, there being no necessity with this adjustment to bend the crutch as heretofore, for the crutch on the verge arbor has a pin screwed into it which communicates the escapement to the adjusting work or pendulum, and keeps it in motion. At the bottom of the pendulum rod is an iron screw and nut by means of which the pendulum bob is raised or lowered, and the clock made to go faster or slower. The motion or dial work for driving the hands are outside at the back of the dials, and consist of two wheels and pinions working in one another, the larger of the two being fitted to a socket and tube. At the other end of this tube is another socket for the hour hand to be fixed to; and through this tube passes another iron rod, at one end of which rod is fitted one of the pinions and the minute hand, the other wheel and pinion being fitted on a socket worked upon a stud in a cock bolted on a bar called the dial bar. If the clock has to drive more than one pair of dial hands, wheels called bevelled or angle wheels are used, which may be cut to suit any angle, so it will not matter how far off the dials may be fitted, or how many they may be, so long as the proper expansion and universal joints are fitted to them. The Hammer-work consists of an iron frame with an arbor pivoted into brass bearings, and upon this arbor is fitted a lever, one end of the lever holding the hammer-head, and the other end raising the hammer. The lifting of the hammer is done by means of a wire from the hammer-tail previously mentioned. There is also a steel spring attached to the lever to prevent the hammer chattering on the bell.

Quarter or Chime Clock.

Quarter or Chime Clocks differ from the above only in having another barrel and train of wheels to provide the extra power for such striking and chiming.

GAS WHEEL FOR ILLUMINATED DIALS.

In instances where it is requisite that the clock face should be visible at a great distance, it is necessary that the dial should be made of semi-transparent glass and be illuminated by gas, which is usually turned as low as possible by day and turned on at night by means of the 24-hour wheel, as shown in the annexed illustration, the time for the turning on being regulated by the man in charge of the clock, who takes out or screws in the pins placed in the rim for that purpose.

NEST OF BEVELLED WHEELS FOR FOUR DIALS.

These wheels should be rather large, inasmuch as they have to carry the hands moving upon the face of the dial. The size of these wheels varies of course with the size of the clock, but they are seldom less than five inches and are generally from seven to nine inches wide.

HAMMER AND BELL.

The next engraving exhibits the relative positions of hammer and bell in a turret clock,—the hammer being fixed at right angles to the swing of the bell, so that the blow of the hammer should not drive the bell out of reach of its next blow, and this position least interfering with the ringing of the bell, when the bell is required to be rung. The hammer spring, as shown, is sometimes so adjusted as to allow of the hammer being brought nearer or further from the bell.

Hammer and Bell.

THE GREAT CLOCKS OF THE INTERNATIONAL

EXHIBITION OF 1862.

BENSON'S GREAT CLOCK.

The movement of this clock, next to that at Westminster, is the largest in the world, and, in point of quality of material and finish of workmanship, it is unequalled by any. The three main wheels are each two feet in diameter, and cast in the solid, of the very finest gun-metal, the teeth being afterwards cut by an engine made expressly for that purpose. The frame is of the best wrought-iron planed to a

Benson's Great Clock.—The Exterior.

Benson's Great Clock.—The Movement.

smooth surface, and by means of a contrivance, known to engineers as plumber blocks, any part of the mechanism may be removed without disturbing the remainder. The pendulum, which is self-compensating, is over 15 feet long, and vibrates or beats once in two seconds. The quarter chimes, which are struck on four bells, are a modification of those of S. Mary, Cambridge.

The great weights necessary to drive so large a clock, and which by the friction they would cause might prejudicially influence its performance, are in this case not allowed to act directly upon the pendulum, but are made to wind up a small auxiliary weight once every half-minute, and this weight imparts an exactly uniform impulse to the pendulum at each vibration. This arrangement, which is called the remontoir, is supplemented in this clock by a double lever escapement of a novel kind, in connection with that known as Graham's Dead Beat.

A CALENDAR AND WIND-DIAL

are useful additions to some edifices. The Calendar indicates on special circles of a large dial—by means of three separate hands—the month of the year, the day of the month, and the day of the week. The peculiarity of this invention is that it needs no correction for the long and short months, nor even for the month of February, with its occasional 29 days; as by means of a wheel cut for the successive months in a period of four years, and which takes that time for a single revolution, the calendar is rendered a perpetual one. The mechanism which directs the pointers to the days of the week and of the month is discharged, by the clock, each night at 12 o'clock, when the levers shift the hands to their proper places on their several dials. On the first of the month all three hands on the dial are moved at the same instant.

The Wind-dial is lettered with the four cardinal points of the compass and the 12 intermediates. The hand which points on the dial is connected by rods and bevelled wheels with a vane at the top of the house, placed 20 feet above the roof in order to be affected, not by wind eddies, but by the true current of air. The connecting rods boxed in the wall are broken at every eight feet with universal joints, and hardened steel is used for all pivots and sockets. The dials are generally made of semi-transparent ground glass and are lit by gas after dark. In a set of Clock Calendars which I some time since provided for His Grace the Duke of Portland, the clock showed the time on four illuminated dials five feet nine inches in diameter, chiming quarters, hours, &c. (the well-known Cambridge chimes) on bells of 12 cwt., repeating the hour after the 1st, 2nd, and 3rd quarters. The two sides of an adjoining tower show a calendar similar to the one above mentioned, with the addition of an extra circle on the dial to mark the age of the moon and the equation of time, so that each dial has four circles, besides the circle of the moon, shifted simultaneously at 12 o'clock every night.

SUN-DIALS

(see illustration on following page) are chiefly used now to mark the solar meridian or noon. Those which indicate other hours have a gnomon with its edge parallel to the earth's axis and inclined to the horizon at the angle corresponding to the latitude of the place in which the dial is fixed.

CARILLON CHIMES.

These beautiful examples of al fresco music, which have been hitherto chiefly identified with Belgium, are now being produced in England with perhaps even more pleasing and satisfactory musical effect. Carillons attached to Church or Turret Clocks are being set up in various churches and mansions in different parts of the kingdom, and it is not improbable that the taste for such chimes may grow with the opportunity for hearing them. As in musical clocks, the works for time-keeping and those for chiming are entirely distinct, with the exception of the means by which the clock at certain fixed intervals lets off the

Sun-Dial.

chiming machinery after the striking is done. Chimes were much more popular years ago than they have been until lately. The old-fashioned machinery used to be rude enough, consisting chiefly of a large wooden barrel, stuck, like that of a musical box, with pins. These pins pulled the hammers that struck upon the bells, and the time was regulated by a rope coiled round one end of the barrel driving two or three wheels connected with a fly-wheel. More recent inventions have improved upon these conditions. The barrel is sometimes of cast-iron instead of wood, with steel or brass pins fixed in it to lift the hammers, and a very heavy weight is necessary to give the motive power. Instead of the ordinary method of raising the hammers and letting them fall by means of the pins on a chime barrel, the hammers are immediately after use returned to their places in striking position ready to be liberated by the pins on the chime barrel, and upon being so liberated are prepared to strike again. The tunes to be played upon these bells will of course be such as are adapted to the particular number of bells in each case, and the cost of the entire chimes depends upon the number and sizes of the bells—so used, varying with the circumstances,—the size and capacity of the tower, and the difficulties to be overcome in providing accommodation for the necessary bells, weights, chime barrel, &c. In each instance, as with turret clocks, the cost of the whole works depends to a great extent upon the cost of fixing the machinery. The tones of the bells have to be carefully provided for, as also the best position in which they can be heard at a distance. With fourteen bells of different sizes almost any tune can be played.

One was erected recently upon the new principle, of which the cost was something under £5000, including 12 bells weighing from five to seven cwt. each, clock, architect's charges, gas-fitting, and £1200 for timber-trussing, floors, &c. The Carillon machine is let off by the clock and plays seven times on the ringing peal of bells, but is adapted to play twenty-eight tunes on fifteen bells. It is wound up every morning and plays eight times in twenty-four hours, i. e. once every three hours, giving the tune on each occasion three times, and occupying about four minutes in doing so. At the expiration of the 24 hours the tune changes involuntarily, and of course with seven tunes there is one for each day in the week. The Carillon machinery is connected with the clock and set in motion thereby, by a lever which at three hours' intervals dislodges a pin and allows the weights, 14 cwt. each, to act upon the machinery, the speed being easily regulated, as in clockwork, by revolving vanes. The barrels are five feet long, by one foot in diameter, and are studded with brass pins like that of a musical box. When the bells are required to be rung, a bar is turned down on the keys which prevents the motion of the machinery for any length of time that the ringing is to be continued. Notwithstanding that the twenty-six hammers weigh from 2 cwt. to 70lbs each, it is possible that the tunes could be played by means of an ivory keyboard, as in a church organ, and with almost as much ease and facility.

Persons requiring to know the cost of a Church or Turret Clock should furnish the Clockmaker with the following data:—

How many Dials?
Their Diameter?
Their Elevation, or distance
from the ground?
If to be Illuminated?
Of what material is
Dial to be?
Can the Movement be
placed on a level with the
centre of Dial, if not, how
far above or below it?
Is the Clock to strike?
if so, on what size or
weight bell?
If to strike halfhours
or quarters, or how many
bells, and their sizes and
weights?
What number of feet
can be obtained for descent
of weights?
What length of Pendulum
will the building
admit of, and is a compensating
Pendulum required?

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