An oil painting of William Thomson, Lord Kelvin, by Harry Herman Salomon. He is older in this painting, with receding hair and a bushy white beard. Kelvin wears a blue-gray jacket and vest, with a white shirt and striped tie. He is working on what appears to be a large dewer - a metallic cylinder with a gauge on its side. Image via the Wellcome Collection.
https://files.mastodon.social/media_attachments/files/110/611/232/562/521/205/original/bc2b439ee8949343.jpeg