William Oughtred document on making a watch ca. 1650

Last updated on July 5, 2020

William Oughtred (1574-1660)

A document I’d like to read some day is a manuscript written by William Oughtred (1574-1660) entitled (in modern English) “Some directions towards the making of a small watch of brass”. It was evidently the subject of an AHS London Lecture on 12 March 2020 by David Thompson.

Oughtred (a mathematician and clergyman who is also credited for inventing the slide rule) had a son (or two) apprenticed to a watchmaker and the feeling is that he wrote the document to help him in his learning of the trade. Oughtred had probably discussed the matter with watchmakers of his time, and essentially written down their collective knowledge for the first time. It outlines how a watch was actually made in London around 1650.

Here is an excerpt from the announcement of Thompson’s presentation on March 12, from the AHS site (it would have been a fascinating talk, unless it was cancelled due to Covid shutdown):

Recently a revealing document has come to light amongst the papers of John Evelyn, which is held to have been written by the ingenious mathematician and clergyman William Oughtred (1574–1660), who is also credited with the invention of the slide-rule in 1622. It is titled Summe Directions Towards the making of a small watche of brasse. Rebecca Pohancenik spent many laborious hours deciphering what has to be described as a challenging manuscript to reveal the secrets held within explaining how a watch movement was actually made in London in about 1650. Whether or not Oughtred was actually skilled in the art of watchmaking, or simply recording the expertise of others, remains as a subject for discussion. Nevertheless the manuscript describes in detail the necessary processes involved. The talk will take a journey through the document detailing how each part of the watch was made, with illustrations of contemporary watches and their components to show the sort of results which were achieved by these ingenious men.

The John Evelyn archive is preserved at the British Library, which is where I presume Ms. Pohancenik was able to consult and eventually decipher the manuscript. Perhaps Pohancenik or Thompson have published (or will in the future) an article on the subject, including the transcription of Oughted’s manuscript for all of us to see and learn from.

In Baillie’s Historical Bibliography of Clocks and Watches, there is an entry for 1674 by Sir Jonas Moore “A Mathematical Compendium…”, where Baillie notes:
Pages 107-120 are under the heading: “Of the nature and making of Watches, Clocks, and other Movements, collected from Mr. Oughtred’s Automata; with several additions and notes about Pendulums.”

From the University of Michigan site, a hyperlink version of Oughtred’s “Mathematicall Recreations”, with the rather lengthy sub-title:
Or, A collection of many problemes, extracted out of the ancient and modern philosophers as secrets and experiments in arithmetick, geometry, cosmographie, horologiographie, astronomie, navigation, musick, opticks, architecture, statick, mechanicks, chemistry, water-works, fire-works, &c. Not vulgarly manifest till now. Written first in Greeke and Latin, lately compi’ld in French, by Henry Van Etten, and now in English, with the examinations and augmentations of divers modern mathematicians whereunto is added the description and use of the generall horologicall ring: and the double horizontall diall. Invented and written by William Oughtred.​

https://quod.lib.umich.edu/e/eebo?idno=A48262.0001.001;iel=4;c=eebo;view=toc

There are some interesting and amusing reference to clocks, including instructions on making a one-wheel clock:

PROBLEM. CIX. How to make a Clock with one onely wheele.
[illustration]
MAke the body of an ordinary Dy∣all, and divide the houre in the Circle into 12. parts: make a great wheele in height above the Axletree, to the which you shall place the cord of your counterpoize▪ so that it may descend, that in 1 houres of time your Index or Needle may make one revolution, which may be knowne by a watch which you may have by you: then put a balance which may stop the course of the Wheele, and give it a regular motion, and you shall see an effect as just from this as from a Clock with many wheeles.

An interesting “biography” of Oughtred can be found in John Aubrey’s Lives. Aubrey had obtained some of the interesting and colourful anecdotes about the old mathematician from his son Ben(jamin), by then an old retired watchmaker with failing eyesight.

The latest issue of Antiquarian Horology has a brief write-up about David Thompson’s presentation on this subject on 12 March 2020. As I quoted earlier, the person who found the manuscript (in a volume of John Evelyn’s papers) and transcribed it is Rebecca Pohancenik (with help from Marissa Addomine).

The presentation writeup offered a few quotes from the transcribed document, which I provide here for the interest of the readers. It will be interesting to see the entire transcript some day, possibly in a future article in Antiquarian Horology.

The great wheel, or fusee wheel, hath commonly 55 teeth, the second wheel 45, the third wheel or Cantrad hath 40, the soggelrat wheel or fourth wheel hath 15.
(“Cantrad” is probably a misspelling of “contrate”. I’ve never seen the old term “soggelrat” for escape wheel!)

The fusee is cast so a dozen maybe cast at once in one piece, one at the end of the other.
(Interesting that the fusee’s back then were cast, I assume the more modern machines to make them were not yet available)

Founders make their moulds with loam and horse dung or fen loam or both, being exceeding well-wrought and laboured together. Fen loam is that which groweth in waters on sedge and of some is called cat’s tails.
Bells as well the greatest as the smallest are best cast in the night time being calm.

(Interest details on bell-making)

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