Alexander Wilson: Observations on the Solar Spots, Philosophical Transactions

London: 1774
Sp Coll HS668-788

Alexander Wilson (1714–1786) became the first Professor of Astronomy at the University of Glasgow  in 1760. A native and graduate of St Andrews, he originally trained as a surgeon apothecary, but left this work to set up a highly successful type foundry in 1742. Wilson also had keen interests in natural philosophy, including astronomy. His knowledge in this area impressed the Duke of Argyll, who wielded influence in the University and ensured that Wilson was appointed to the new Chair of Astronomy. The Professor was to take charge of the new Dowhill Observatory and concentrate on observation rather than teaching.

This is Wilson’s first publication on sun spots, based on his solar observations at Dowhill. He thought that the sun was a dark globe with an irregular surface, surrounded by a somewhat fluid luminous matter. He proposed that sun spots were “immense excavations in the body of the sun”. These allowed the dark surface to show through in places, contrasting with the luminous matter. Wilson summarises the properties of these sun spots as they wax and wane, and tentatively explains the phenomenon. Wilson’s hypotheses remained influential until they were convincingly disproved in the 20th Century. This copy contains markings and emendations in ink and pencil - possibly by the author, perhaps with a view to a corrected edition.  

 Diagram from Alexander Wilson's ‘Observations on the Solar Spots’
Image: page of text with fold-out diagram, depicting solar spots as excavations.

Go to the next book in the exhibition: Alexander Wilson: Thoughts on General Gravitation