Portrait of a Mathematician by Mary Beale (1633 - 1699)
Conjectures to be of Hooke, or possibly Barrow
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An imagined portrait of Hooke by Rita Geer
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A spurious portrait from Time magazine in 1939
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The portrait above was discovered recently after being missing
for a long time and was initially claimed to be of Hooke; but is now
believed to be of the Dutch chemist van Helmont