Talk:Verge escapement

What about the foliot?

This article fails to mention that for 300 years before the invention of the pendulum, the verge escapement was used exclusively with the ‘foliot’ timekeeper in the 'verge and foliot' regulating mechanism. ‘Verge and foliot’ is the common distinguishing term for clocks of that construction. The article doesn’t mention the foliot at all, even though the Wikipedia heading ‘foliot’ and 'verge and foliot' redirect here. The historical importance of the verge is inextricably linked to the foliot, because the first mechanical clocks in the world were verge and foliot types. The early clocks mentioned, the Villard de Honnecourt and Salisbury Cathedral clocks, used verge and foliot. In contrast, the use of verge escapements with pendulums was quickly superseded (within about 50 years) by the anchor escapement, as the article says.

A casual reading of the article might give the impression that the only important use of the verge escapement was with pendulum clocks. Admittedly, in the technical clock collecting and repair fields, the word verge is considered part of a pendulum clock, because there are many more verge pendulum clocks in existence. But historically, the verge is much more associated with the foliot. Encyclopedia Brittanica weight driven clock article refers to ‘verge' almost exclusively with 'foliot'. I did a Google search on ‘verge’ and ‘clock’. Out of the first 28 results, 17 used ‘verge’ only in connection with ‘foliot’.

I understand the intention was to limit the scope of the article to the escapement mechanism (verge) regardless of the timekeeping mechanism (foliot or pendulum) used with it. But not mentioning the foliot at all risks misunderstanding this important technological breakthrough. --Chetvorno 01:55, 2 June 2007 (UTC)

Rewrote article 8 June 2007 to add section on verge and foliot clocks --Chetvorno 01:05, 18 August 2007 (UTC)

Change reference citation style?

If nobody minds, I'd like to change the reference style from the Harvard format to the more common footnote format. I tried the Harvard here as an experiment. But the Harvard template requires every citation's source to be listed under 'References', and the number is getting large. With the footnote style, only the major refs need to be there. --Chetvorno 12:08, 25 October 2007 (UTC)

Done. --Chetvorno^TALK 17:33, 13 November 2007 (UTC)

Animation

This article would greatly benefit from having a small animation of how it works — Preceding unsigned comment added by 198.240.128.75 (talk) 14:04, 16 January 2012 (UTC)

Recently added accuracy claim

David.Boettcher, was the "minutes per day" accuracy claim in both the sources based on tests of actual clocks from the 14th century? And did the accuracy apply to operation over a typical day-to-night temperature range in an unheated building? And how many minutes error did they find? --Chetvorno^TALK 21:35, 21 July 2014 (UTC) Email me for more details; I'm not difficult to find. David.Boettcher (talk) 12:53, 23 July 2014 (UTC)

Recent changes to text

@Elias Tawfik:, User:200.52.56.29 Thanks for the edits correcting my description of the escapement. The way I used 'verge' was ambiguous. However part of the description you added is misleading; the phrase: "...braided string responsible for the oscillations of the verge-foliot apparatus as it twisted and untwisted.". This sentence is going to give readers the erroneous impression that the twisting string provided a restoring force, like a hairspring, returning the foliot to its center position.

This is not the case for three reasons: (1) Many verge escapements did not use strings to suspend the verge (see pictures) (2) the narrow string or thread that was used, even if braided, could not exert enough torque on the heavy foliot to reverse its rotation, and (3) even if it could, the verge escapement was constantly pushing on the foliot and did not allow it to swing freely during any part of its cycle, so it could not be affected by the torque of the string. When an escape wheel tooth slipped off the pallet after pushing the foliot in one direction, a tooth on the other side immediately dropped onto the other pallet and began pushing the foliot in the other direction. The motion of the foliot was totally controlled by the force of the escape wheel and the moment of inertia of the foliot. That's why the verge and foliot was such a poor timekeeper, it was a relaxation oscillator so changes in the drive force caused the clock to speed up or slow down. The addition of the balance spring in 1657 for the first time provided enough restoring force to make the balance wheel a harmonic oscillator with an inherent resonant frequency, resulting in an enormous increase in the accuracy of watches and clocks. The lack of restoring force in the verge and foliot is widely known and mentioned by reliable sources Du, p.8, Marrison, p.314-315, Glasgow, p.12, NIST Chetvorno^TALK 01:27, 21 April 2021 (UTC)

Corrected it --Chetvorno^TALK 16:18, 6 May 2021 (UTC)

Not ALL modern clocks use oscillators

The final sentence of the lede makes the claim that "Oscillating timekeepers are used in all modern clocks." This is incorrect, so I qualified it by adding "mechanical", as in "Oscillating timekeepers are used in all modern mechanical timepieces". User:Chetvorno reverted this, claiming that "Oscillating timekeepers are used in all modern clocks." This is patently false. There are indeed modern timekeepers which do NOT have oscillators. To cite just two examples: clocks with synchronous DC motors were the most common kitchen clocks in the US between the 1930s and 1980s. And here is an electronic digital clock that likewise has no oscillators; it simply uses the incoming AC current at 50 (or 60)hz and decade dividers to drive the readout: [1]https://hackaday.com/2010/04/07/logic-clock-without-an-on-board-oscillator/ No, these are not clocks with oscillators; they are clocks without oscillators that happen to tap into the oscillations of externally-supplied DC power. That is not a trivial difference. Consequently I am going to change the sentence in question to read as follows: "Oscillating timekeepers are used in most modern clocks." (emphasis added) Anyone who wants to revert this had damned-well better debate it here first. Bricology (talk) 09:55, 26 September 2023 (UTC)

Oscillating (resonant) timekeepers keep time for all modern clocks:

• Jespersen, James; Fitz-Randolph, Jane; Robb, John (1999). From Sundials to Atomic Clocks: Understanding Time and Frequency. New York: Courier Dover. p. 39. ISBN 978-0-486-40913-9. Archived from the original on July 3, 2023. Retrieved October 30, 2020.
• Bloomfield, Louis (2007). How Everything Works. Wiley. p. 296. ISBN 978-0-470-17066-3. Retrieved March 19, 2023.
• Marrison, Warren A. (July 1948). "The Evolution of the Quartz Crystal Clock". Bell System Tech. J. 27 (3): 511–515. doi:10.1002/j.1538-7305.1948.tb01343.x. Retrieved February 25, 2017.
• "Clock". Glossary, Time and Frequency Division. US National Inst. of Science and Technology. Retrieved 13 August 2024.
• Mondschein, Kenneth (2020). On Time: A History of Western Timekeeping. Johns Hopkins University Press. p. 88. ISBN 978-1-4214-3827-6.
• Stehle, Philip (1971). Physics: the Behavior of Particles. Harper and Row. p. 59. ISBN 9780060464110.

The synchronous clocks you mention are controlled by an oscillator; the master oscillator which the electric power grid uses to keep their alternating current on frequency. The oscillator is just not located inside the clock's case. This is a trivial difference. Your version: "Oscillating timekeepers are used in most modern timepieces" misleads general readers to think some modern clocks use some other timekeeping mechanism. --Chetvorno^TALK 19:15, 13 August 2024 (UTC)

Also, there is no such thing as a "synchronous DC motor". The "Logic clock without an onboard oscillator" project you linked does not run on DC, it says it gets its timing signals from the 50Hz AC line, in other words from the power grid's master oscillator. --Chetvorno^TALK 09:06, 18 August 2024 (UTC)