Thoughts on an interesting regulator with Epicyclic maintaining power.
John Brown – Southampton (Hants) 1830
Epicyclic maintaining power is a very rare feature. Although used in turret clocks (mainly by Cooke and Sons of York), it is seen in only a handful of clocks of this type. It was known to have been used by Cooke and Sons on a couple of their very fine astronomical regulators and is fitted to two clocks by Vulliamy, one in the Royal collection, and the other in the Science museum. The latter had originally been fitted with bolt and shutter maintaining power, however, this was replaced by the epicyclic system suggesting that at the time the system must have been seen as a technical advancement and worth upgrading to. Thought to have been first described by Christiaan Huygens in 1683 it was in use in early watches and (in a modified form) seems to have been employed as a system to enable winding in both directions. Both Thomas Reid and Lord Grimethorpe describe the system in their Treaties as follows:
“There is a very ancient way of going while winding, which was long applied to the fusees in clocks and watches. On the inside of the great wheel is another wheel, whose teeth are cut to look inward to the centre, upon which acts a pinion of six, which runs in the bottom of the fusee, and is turned around with it. The fusee arbour is free within both the great wheel and the fusee; upon it is fixed the fusee ratchet and a wheel with about half the number of teeth of those in the inward toothed wheel. It is evident, that if the fusee arbour is turned around, the wheel fixed on it, which acts also on the pinion of six, will by this make the pinion turn; and this again, acting on the inside wheel teeth, will apply as much force to it as the fusee requires in setting up. When wound up, the click in the great wheel, as in the ordinary way, stops the fusee by the ratchet from running back. This method takes six times longer of winding up than by the common way, and the great strain which is laid on the pinion and inside wheel teeth soon destroys them. With a little more apparatus, a fusee of this kind can be made to wind up whichever way the arbour is turned; hence it got the name of the drunken fusee.” - Thomas Reid – Treaties on Clock and Watch Making.
“There is another maintaining power which has a tempting and scientiﬁc look but is not so good as it looks. A rim at the back of the great wheel, M (ﬁg. 30), has internal teeth at A—troublesome things to make—and in them works a wheel ABP on a stud B in the end of the barrel, and also in a pinion C ﬁxed on the arbour which runs loose through the barrel ends. When you wind up you apply some force P to the intermediate wheel, and the same pressure P is communicated to the great wheel because BP = BA, P being whatever is necessary to lift the weight. Let W be the eﬀective weight at A when the clock is going: at B it is WCA CB = W0; and P = W0 2 , since AP = 2AB ... P = W 2 CA CB; which cannot possibly = W, however small the winding pinion is, and if it is very small it takes a long time to wind. So this maintaining power must be deﬁcient, though it may do for clocks with the common escapements, which will go for a few minutes with very little power on. Besides that, the winding arbour has to work under double friction of the pressure of twice W, both above and below it. For all these reasons I have never adopted it, either for large or small clocks.” - EDMUND BECKETT, LORD GRIMTHORPE – Clocks, Watches and Bells.
Although obviously in use long before Harrison's superior invention, it would seem to have been viewed as unsatisfactory in the long term. The properties of the transition of power through the satellite pinion on the inside of the great wheel makes it prone to extreme wear and jamming.
The clock we have just restored displayed just that fault. The fixed pinion had a number of its teeth broken off and as a result, it had been disabled. Luckily the repairer had achieved this in a completely reversible way. He had pinned the fixed pinion to the barrel thus stopping the arbour from rotating. He had also removed the satellite pinion (presumably also broken) and thus easily converted the system to a conventional click. This obviously left the clock with no form of maintaining power. As this clock possesses a rather fine deadbeat escapement with a heavy pendulum it was thought to be a bad idea to leave it minus its maintaining power and so we have restored the epicyclic system.
This involved making a new pair of pinions (in this example 1:1 count), removing the fixing pin and plugging the hole, and repairing the click and post. We made the new pinions of a hard grade of modern brass to help give some wear resistance to the setup. Cast ‘yellow’ brass, although correct for the original construction would have been a very poor choice due to its soft and brittle (due to being very porous) character.
The clock is now restored to what must be one of only a very few working examples of a regulator with intact epicyclic maintaining power.
The pendulum on this clock is also of great interest. It is of a design by Ward and is a serious attempt at compensation. It has three rods, two of steel and an internal one of zinc. The system is described in Rees’ Clocks Watches and Chronometers.
“In March of the year 1806, Mr Henry Ward, of Blandford Dorsetshire, communicated to the Society of Arts at the Adelphi, an account of a new compensation pendulum, accompanied by a model, which gained him the silver medal from the society.”
I have yet to see another example of this type pendulum, although a clock described as being by Ward, although signed by Francis Jones is known to exist and is described as employing “Ward’s own design of compensated pendulum, epicyclic maintain power and deadbeat escapement”. The discovery of the existence of this clock is most interesting as it presents the question – was our clock made by Ward? If he was known to have sold at least one clock to be signed by another, which is described as being exactly the same specification as this one, then perhaps it’s a fair assumption that this clock was also signed by another.
Blandford (Wards hometown) is some 42 miles west of Southampton and therefore not an inconceivable journey across the New forest for a suitably high-grade clock from a prize-winning maker.
This has led to consideration of Wards work. A clock is pictured in Roberts’ ‘English Precision Pendulum Clocks’ and displays some very similar characteristics. The dial, although very different in design, is extremely similar in style with the engraving and hands both being very similar. The case is also very similar, although not identical.
Henry Ward of Blandford was born in 1776 and lived to just thirty-nine years old. He obviously possessed a considerable horological mind with three most interesting technical inventions to his name, including the pendulum used in this clock, for which he won a silver medal and five guinea prize! His clocks were known to include many ingenious features.
Little is known of John Brown of Southampton, other than the fact he was working circa 1830. It is estimated that this clock was made slightly before that date – circa 1815. A clock such as this demonstrates that it was made by a serious maker working at the top of his trade. The very fine (if slightly unusually designed) case demonstrates that this clock was obviously made as a fine astronomical instrument. The movement is massively constructed and shows very fine workmanship and artistic detailing. The technical inclusions such as the epicyclic maintaining power, rollers on the barrel bearings, and a serious compensating pendulum show that the maker was in touch with the leading advancements in this technology. Why he didn’t use Harrisons maintaining power in 1830 is not known. Perhaps he preferred the older system, or perhaps that was an advancement yet to make its way to his workshop.
All this gives the impression that this clock was made by Henry Ward and sold by, or perhaps made for John Brown of Southampton. One could speculate that because this clock dates to around the time of Wards’ death, was it a stock piece sold off to another local maker to complete and sell? The clock signed by Francis Jones may have a similar history. Perhaps we will never find out for certain, however, the search is on to find details of other examples of Ward’s work to help confirm this assumption. I would be most grateful to hear from anyone who has any information on any of the makers mentioned.
Reid, Thomas. (1832) Treatise on Clock and Watch Making. Chapter II p275.
Thiout. (1741) Traite dHorlogerie Mechanique et Pratique. Vol II p333. Plate XXXVIII Fig. 14.
Roberts, Derek. (2003) Precision Pendulum Clocks. Chapter 4 p65. P88 fig 5-24
Roberts, Derek. (2003) English Precision Pendulum Clocks. Chapter 7 p103 – 106 Fig 17-5A
Good, Richard. (1998) Henry Ward of Blandford, Dorset. Horological Journal. May 1998 pp 156 -159
Good, Richard. (1998) Henry Ward of Blandford, Dorset 2. Horological Journal. June 1998 pp 192 -195