Scottish Natural Philosopher – George Sinclair [?1630]-1696

Friday 31 August 2018
Title page of The hydrostaticks; or, The weight, force, and pressure of fluid bodies, made evident by physical, and sensible experiments, 1672 (For QC143.S6)
Title page from The Great and New Art of Weighing Vanity,  1672 (TypBG.C72RG)

George Sinclair was one of the earliest British writers on hydrostatics and published The hydrostaticks in 1672. At the time, Sinclair’s work was criticised by James Gregory and William Sanders in The Great and New Art of Weighing Vanity of 1672. In a recently published article in Notes & Records of the Royal Society, “The hydrostatical works of George Sinclair (c.1630-1696): their neglect and criticism“, Alex Craik (Emeritus Professor of the School of Mathematics and Statistics) looks at the work of the 17th century scholar and the criticism it received. While Alex Craik was researching the historical background of Sinclair’s life, he discovered a mystery regarding Sinclair’s education and brought it to our attention.


Sinclair was student at the University of St Andrews. In the joint matriculation and graduation records of the University of St Andrews, George Sinclair’s signature appears in the session 1645-1646. Sinclair matriculated into St Leonard’s College but did not graduate, appearing only once in the matriculation records. Later, he worked as a ‘pedagogue’ at St Andrews before being appointed a Regent at Glasgow University in 1654.

George Sinclair’s signature (7th signature from the top of the image) in the University of St Andrews Joint Matriculation and Graduation roll, 1645-1646 (UYUY305/3)

It was unknown where he received his further education, though it has been suggested that he may have gone to Holland. In David Clarke’s Reflections on the Astronomy of Glasgow it is suggested that George Sinclair matriculated at Edinburgh University in 1647 and graduated with an MA in 1649. This fits well with his year in St Andrews.

In the Edinburgh University First Laureation Album, 1587-1809, George Sinclair’s signature can be found in 1649.

Page from the University of Edinburgh Laureation and Degrees Album, 1587-1809 (original image available here)

His class begins halfway down the right hand page of the spread, where it says “61 Classis M. Duncanus Forresterus 26 Julij 1649”. The names which follow are the signatures of that year’s graduands. George (‘Georgius Sinclarus’) is the 10th signature in the list. However, the signature on the Edinburgh laureation album is very different from later signatures, and Craik first suspected that this was someone else with the same name.

Images of the various Sinclair signatures from the Universities of Edinburgh, Glasgow and St Andrews were acquired and it became clear that his St Leonard’s matriculation signature resembles the Edinburgh one. It is possible that he may have used two signatures around this time, one in secretary hand and the other italic, before switching to sole use of italic style.

Signature from the University of St Andrews 1645-1646
Signature from the University of Glasgow 1654

Rachel Hart who teaches Palaeography at St Andrews commented to Alex:

I am sure that the St Leonard’s signature is the same signature as appears in the Edinburgh record of 1647. However, the later, Glasgow, signatures are, as you say, quite different. They are much more italic or simplified in style. Palaeographically there are some slight similarities – in the curled flourish off the top of the capital G which remains in the 1650s version, and in the elaborated capital S which is made up of a double ‘S’ in the early hand and a rather stylised doubling which looks a little like a treble clef. However, I would not like to commit to the same man having done the St Andrews and Edinburgh signatures as the Glasgow ones.


While it is possible that Sinclair switched to a more italic style of hand later in life, more evidence would be required to say conclusively that these signatures are all from the same hand. The mystery of the two different signatures remains unsolved and highlights the importance of palaeography in historical research.

To practice your own palaeography skills have a look at Readme!, an online resource developed by the University of St Andrews to assist in palaeography teaching which is open to all:

Related topics

3 thoughts on "Scottish Natural Philosopher – George Sinclair [?1630]-1696"

  • Julie Goldsworth
    Julie Goldsworth
    Saturday 13 July 2019, 9.37pm

    Any chance you know more about George Sinclere/Sinclair? Roland William Saint-Clair's "St. Clair's of the Isles" mentions a George Sinclare, Professor at Glasgow University. 1654 - 1696. "George Sinclair or Sinclare, brother of the Rev. John Sinclar, Regent of St. Andrew's , elected Professor of Philosophy in the University of Glasgow 1654, and ejected in 1662 for refusing to comply with the episcopal form of church government, was restored in 1688, and retained his professorship (to which in 1691 that of mathematics was added) until his death in 1696." Is this the same George Sinclair? Do you know what he did between 1662 and 1688? Do you know anything about his family? Thank you for this article! Julie Goldsworth

    • St Andrews Special Collections
      St Andrews Special Collections
      Monday 15 July 2019, 11.03am

      Hi Julie, thanks for your question. I believe this is the same George Sinclair. If you have a look at Alex Craik's article ( he discusses what Sinclair did between 1662 and 1688 in the section 'Sinclair's life and works'. If you have any further queries, please let us know.

  • Glenda Shryock Reed
    Glenda Shryock Reed
    Saturday 7 May 2022, 4.15pm

    I Am writing a book, purely fiction but using George Sinclair as the main person. about a swinging bridge that he supposedly built. The bridge was supposedly haunted. with many young ladies jumping to their death from this bridge, Ladies with husbands to be also jumped committing suicide together. is there any history about this? Or did I dream it? I Am an author of 8 books of fiction, but I like going back in time with my story. thanks Glenda Shryock Reed


Leave a reply

By using this form you agree with the storage and handling of your data by this website.


Enter your email address here to receive notifications of new posts by email.

Join 6,499 other subscribers.