[The Horological Journal. Vol. ??, No. ?? (March, 1878): 86-88.]
(Continued from page 79.)
AS to the date of invention of the Remontoire principle: BERTHOUD, in his Histoire de la Mesure du temps par les Horloges,1 quotes the following from a Memoir signfié par la communauté des Horlogers de Paris contre Pierre Rivas T1, 1751: "An old German clock, made about A.D. 1600, and the balance of which was à foliot (this is a mistake, says Berthoud, foliot simply means regulator or balance), which proved its antiquity, belonged to M. le président DE LUBERT. It struck the hours and quarters, and was `astronomical,' a remarkable circumstance in those days. The pins of the striking part re-wound at each quarter the spring-of-the-going-part, which was contained in a little barrel. This invention was applied by its author to the clock solely to give it greater regularity by making the wheel-work pull more equally," and continues "if this is true, which one cannot doubt, the invention of the Remontoir d'egalité T2 is very ancient, and the clock made in Germany about A.D. 1600, is the first known in which the arrangement is applied."
The celebrated Christian HUYGHENS is the first who, in print, writes about the remontoire. In his elaborate and beautiful work, De Horologio Oscillatoire, he gives a short description, but without drawings (page 18): "I attach to the crown wheel by means of a well finished cord a small weight, which alone moves this wheel; the rest of the clock is employed in re-winding up at each vibration this weight to the same height in such a manner that when one pulls one of the cords the motive power acts, nevertheless, always in the same way on the wheel work. This new arrangement produces a much more constant force in the machine."
[This is a smaller copy of Figs. 1 and 2 (reproduced full size below) for easier reference from the text.]
HALEY'S (figs. 1 and 2) maintainer is the helilcal spring R on the arbor of L M N; train is locked by 'scape-wheel E on detent D. Maintainer is locked by tooth N on detent a. [Detents a and D have banking pieces with adjusting screws, of course, as usual.] [Note by the transcriber - the [square braces] used above appear in Frodsham's original text.] I is the discharging pallet, and K is the impulse pallet of the balance T.
Fig. 2 shows the maintainer locked up, having just been armed by the action of a tooth of 'scape-wheel E on the pallet of roller M, the balance, moving towards the left discharging pallet I, lifts detent a (the fig. is incorrectly drawn)2 maintainer thus released (i.e., tooth N from detent a) gives impulse to the balance by tooth L's action on impulse pallet K.3 [Transcriber's note: The paragraph above does not appear grammatical to me, unless it is taken as three sentences rather than one, but is transcribed exactly as printed.]
After it has given impulse another discharging pallet at N will unlock detend D, and so allow another tooth of E to fall on impulse pallet of M, and re-arm the maintainer. The return vibration of the balance merely lifts the passing spring of detent a.
Observe the different planes of the parts in the figures.
[Figures 1, 2, 3, and 4 originally appeared together in and comprised the entirety of page 87.]
FIG. 1. [and] FIG. 2.
[This is a smaller copy of Figs. 3 and 4 (reproduced full-size below) for easier reference from the text.]
Figs. 3 and 44 show the escapement for which MUDGE5 received the award of £3000, or, rather, he received £500 in 1777, and his son the balance on the recommendation of the Parliamentary Committee in 1793, but this beautiful piece of mechanism is so complicated that the young Mudge could not make chronometers fitted with it to pay him at 150 guineas apiece, and much as it must excite our admiration, both for the mind which invented it and the way in which its details were carried out, 6 it did not go as well as the simple detent escapement.
Springs H and I are the maintainers. H actuates the arm a of the top part of the cranked (E F) piece of the balance staff by means of figer b, which projects from the [Page 86 ends here; page 87 contains Figs. 1, 2, and 3; the text resumes on page 88] arbor, pivotted at c and d, on which H is fixed.
I is fixed on arbor of finger f, pivotted at g, and gives imipulse to arm e of E F.
On the arbors of b and f are fixed the pallets (fig. 4); the maintainers are armed by the action of the teeth of the crown 'scape-wheel G, and, after arming, the tooth is locked on the nib at the end of the pallet; the arms a and e come alternately in contact with their respective maintainers' fingers, and release the train, and when the balance returns the tension of the springs H and I is communicated to it, and so its vibrations are maintained. The arc of movement of the balance is necessarily limited in this escapement. There are six pivots in motion with the balance; the arrangement of the cocks is most complicated.
FIG. 3. [and] FIG. 4.
[Below is a smaller copy of Fig. 5 for easier reference from the text, along with a copy of Fig. 8 from p. 77 in the February, 1878 installment of this series, for reference as suggested in the text.]
[Fig. 5, small]
[Fig. 8 (small) from p. 77, February, 1878]
Compare MATHEW'S, page 77. Fig. 5 is designed to serve as a disentanglement of the numerous planes of MUDGE'S escapement, not as a practicable escapement. Ruby pin i (answering to a and e, fig. 3) has just received impulse from M (answering to finger f) owing to the released tension of spring S' (answering to I); the 'scape-wheel W (G) has just tensed S by lifting pallet p'. Ruby pin i at the end of its vibration will lift and release pallet p', and be impulsed by the stored-up force of S, when it begins its return vibration.
1 Published at Paris 1802 (see Vol. II., p. 41).
2 This figure is repeated, with slight alterations, from Vol. I., p. 148.
3 Specification, No. 2132. A.D. 1796.
4 This block is reproduced from Vol. II., page 17.
5 Line 40, page 22, instead of "C.G.Mudge's escapement," read "e.g., Mudge's escapement."
6 The Horological Institute has a chronometer with this escapement on, and the Clockmaker's Company have an original escapement taken from an old Mudge chronometer. An inspection of them will gladden the eyes of lovers of good watch-work.
[Notes by the transcriber, who does not read French]
T1 In the original text, the accent on the final 'e' of "communauté" does not appear to be an ordinary acute accent but rather a smaller, more vertical accent. It appears thus:
This accent is neither an acute accent like the one appearing on "signifié" in the image, nor an ordinary grave accent like the one appearing in the phrase "à foliot," as reproduced below:
T2 The same accent described in note T1 above appears also in the phrase "Remontoir d'egalité," as reproduced below:
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