The second point to be explained is the maintaining-power device before alluded to. It must be obvious that as the motive power of a clock, of the kind we are considering, consists in the fall of a weight, when we wind the clock we lift this weight with the winding-key, and the power is temporarily removed. A long pendulum will usually swing through this period by its own momentum, but the clock, especially if it be finely adjusted, will not keep time during the period of the winding. The margin of error will be very slight, but the old clockmakers prided themselves on the accuracy of their clocks, and to overcome this defect the maintaining power was adopted. This provides a pulling-string or a depressing lever, putting in operation a spring, which acts on the going train, thereby driving the clock by spring-power during the period while the driving weight is being lifted on the winding-key. To ensure that this spring-power shall be used without any option on the part of the person winding the clock, shutters are provided in front of the winding-holes - which in some measure protect the clock from dust - and these shutters can only be opened for the winding of the clock by putting the maintaining power into action, either by pulling a string or depressing a lever. In Fig. 394 the winding square is hidden by this shutter. (The clock, being a non-striker, has only the one winding-hole.) The dial measures 10 ins. square, and the train has been "planted" to occupy part of the space which would have been required for a striking train. Fig. 395 shows the clock in its case, the latter being of oak veneered with burr walnut. The hood has no door, and is made with grooves in the back to slide up for winding, a click-spring being provided to hold the hood up during this operation. This is the usual device with early long-case clocks.
Fig. 396 is a Tompion dial of the same early date, measuring only 9 1/2 ins. square, and with the refined narrow hour ring of that period. The hands are exceptionally delicate, and the dial-plate is water-gilt, in a similar manner to the Clement dial, Fig. 394. Fig. 397 shows the case, of simple burr-walnut veneer, the only extra embellishment being the carved cresting to the hood. It will be observed that these early clocks, of superfine quality, were rarely put into elaborate cases. I do not think that Thomas Tompion ever had a marqueterie case made for any of his "Grandfather" movements. Walnut or ebony veneer, the cases either plain or panelled, and sometimes, as in this example, a carved cresting to the hood, were the only enrichments he appears to have tolerated.
He evidently regarded, - and rightly too, the clock itself as being the main point of interest, and all elaborations of detail, finish and workmanship were lavished on the dial and the mechanism behind it. The next two examples, shown in Figs. 398, 399 and 400, clocks by Joseph Knibb from Mr. Wetherfield's collection, are exquisite illustrations of this point. Nothing could be finer than the Knibb dial, Fig. 398. The hour and the seconds circles are of solid silver, the dial and its beautiful corner-pieces, water gilt. Both hour and minute hands are exceptionally beautiful even for this age of fine clock-making. The striking is on two bells of different tones, and the clock strikes in Roman numeral fashion, an innovation which originated, as far as I know, with Joseph Knibb. Thus the deep tone bell is struck once at five o'clock, twice at ten. One, two or three blows on the small bell marks the first hours; four o'clock is sounded by one blow on the small followed by one on the large bell. One on the large followed by one on the small marks six o'clock; one on the small followed by two on the large is nine o'clock, and so on. A simple calculation will show that only thirty blows are struck by this method as compared with the usual seventy-eight in the twelve hours, a valuable economy in power. Considering that this Knibb clock is of month duration, and the striking has to function with the going train for the same period, the value of this striking system will be apparent in a clock of this size, as the case only measures 6 ft. 8 ins. in height, which precludes any undue length of the gut line on the barrel of the striking train. The dial is 10 ins. square. The case, Fig. 399, is veneered and panelled with ebony with the metal mounts water gilt. In my opinion this is one of the four finest examples in Mr. Wetherfield's collection. Of similarly high quality to Fig. 399 is Fig. 400, also from the hand of Joseph Knibb. The case is veneered with ebony, the mouldings faced from solid wood, and the caps and bases of the hood-columns are of chased brass, water gilt. The spandrel-corners of the dial are engraved, in the early fashion of Fig. 392; the hour circle is narrow, the dial finely matted and water gilt, and the movement has the bolt-and-shutter maintaining power. This clock, in my opinion, is not only the earliest, but also the finest example of Joseph Knibb's work possessed by Mr. Wetherfield, even among the unique specimens which the collection contains, the previous example alone excepted. I have recently discovered that Quare copied this Roman numeral striking from Knibb. Mr. James Stuttard of Fence House, near Burnley, has kindly lent me two photographs, reproduced here in Figs. 401 and 402, which show the dial and the side view of a month clock by Dan Quare, and the IV on the dial, instead of the usual IIII, indicates the adoption of this Roman numeral system of striking. (It is surprising, by the way, how many people will write the " 4 " as " IV " if they are asked to number a dial from memory. Actually this is always engraved "IIII" in any but dials of clocks striking on this plan.) The dial of this Quare clock is signed "Dan Quare, London," and above is the Roman figure III. This probably indicates that this clock is the third made by Quare on this system.