Perigal, Henry Jr (1801-1891) Stockbroker, Mathematician and Astronomer

**Mathematical visiting cards and pamphlets on the Moon Controversy**

*London, 1860’s,*

Three visiting cards of Henry Perigal

1. displaying his proof of the Pythagorean theorem based on the idea of dissecting two smaller squares into a larger square, and printed with the formula B2+P2=H2.

2. with a proof(?) of the formula 2y2=R(R=x)

3. a pattern of mathematical curves inspired by ornamental lathe turning, a hobby of his, [WITH] ‘The Moon Controversy’ from the Astronomical Register for March 1864, 4pp, 4to, reprinting a group of letters refering to Perigal and the controversy,

**[WITH]** Five, double sided printed sheets, each explaining and elaborating on Perigal’s proof of the non-rotation of the moon, variously published 12th and 21st February 1864 Perigal worked as a clerk for the Privy Council and became a bookkeeper in a London stockbrokerage in the 1840s. He was a member of the London Mathematical Society from 1868 to 1897, and treasurer of the Royal Meteorological Society for 45 years, from 1853 until his death in 1898. He was elected as a fellow of the Royal Astronomical Society in 1850. He attended the Royal Institution as a visitor for many years, and finally became a member in 1895, at age 94. Perigal believed (falsely) that the moon does not rotate with respect to the fixed stars, and used his knowledge of curvilinear motion in an attempt to demonstrate this belief to others. He also was an accomplished lathe worker, and made models of mathematical curves for Augustus De Morgan, mathematician and logician.

**[ref: 12563] £750 (8 items)**