Early Georgian Portraits Catalogue: Canton
The following text is from the National Portrait Gallery collection catalogue: John Kerslake, Early Georgian Portraits, Her Majesty's Stationery Office, 1977 (now out of print). For the most up to date research on the Collection, we recommend reading the information provided in the Search the Collection results on this website in parallel with this text. This can be accessed by following the link with each portrait’s title.In consulting the following, please note that apart from the reformatting which allows the printed catalogue to be made available on-line the text is as published in 1977. Footnotes in the original edition are given within square brackets.
John Canton (1718-72)
Scientist; weaver's apprentice from Stroud, moved to London, 1737; became a schoolmaster; conducted valuable experiments in electricity and magnetism; FRS 1749.
809 By an unknown artist
Oil on canvas, now 19 ¼ x 15 ½ in. (488 x 394 mm); greyish-brown eyes, nose somewhat retroussé, full lips, long grey wig; dark grey coat, unbuttoned but not open, no collar, plain white cravat; behind his head, dark green curtain partly conceals two books; bottom left, the left-hand spine lettered PRI [ . . .]/ 2;  lit from the top right.
NPG 809 is only a head. The picture, according to Robert Canton, great-grandson of the sitter and donor of the picture, 'was originally full length, sitting in a chair with legs crossed and surrounded by mathematical instruments I think'. The son William, it seems, had inherited the portrait and 'spent his life travelling about, and at first carried it with him in the frame. Ultimately the frame was abolished and finally the head cut out of the canvas, in which state it descended from my father to me.' 
No other version is known apart from the picture sketched by Scharf in 1869  at Alfred Canton's,  a dentist, 17 Great Marlborough Street. This was in a black painted oval; no books are shown, and it is almost certainly not NPG 809. James Yates, the antiquary, who collected information for a life of John Canton, suggested to the donor in 1871 that it was 'probably painted for some Club', perhaps Batson's Coffee House, or the Queen's Arms, Newgate Street to which the sitter may have belonged. This has not been substantiated. Nor is there any mention of the portrait in the Canton papers at the Royal Society, of which the sitter was three times president.
Condition: ultra-violet light reveals many retouchings in the face; surface cleaned 1895; relined, polished and varnished, 1896; it is not known precisely when it was cut down.
Collections: received, 1888, from Robert Canton.
Iconography No other portrait of the sitter is known or recorded.
1. Now almost completely illegible.
2. Letter to Scharf, 4 September 1888, NPG archives.
3. TSB, XV, 63.
4. The donor's cousin, then head of the junior branch of the family.
5. Copy of letter, 8 January 1871, NPG archives.