William Herschel
Astronomy

Herschel's reading in natural philosophy during the 1770s not only indicates his personal interests, but also suggests an intention to be upwardly mobile, both socially and professionally. He was well-positioned to engage with eighteenth-century "philosophical Gentleman" or philomaths, of wide-ranging logical and practical tastes. Herschel's intellectual curiosity and interest in music eventually led him to astronomy. After reading Robert Smith 's Harmonics, or the Philosophy of Musical Sounds (1749), he took up Smith's A Compleat System of Opticks (1738), which described techniques of telescope construction. He also read James Ferguson 's Astronomy explained upon Sir Isaac Newton's principles and made easy to those who have not studied mathematics (1756) and William Emerson 's The elements of trigonometry (1749), The elements of optics (1768) and The principles of mechanics (1754).

Herschel took lessons from a local mirror-builder and having obtained both tools and a level of expertise, started building his own reflecting telescopes. He would spend up to 16 hours a day grinding and polishing the speculum metal primary mirrors. He relied on the assistance of other family members, particularly his sister Caroline and his brother Alexander, a skilled mechanical craftsperson.

He "began to look at the planets and the stars" in May 1773 and on 1 March 1774 began an astronomical journal by noting his observations of Saturn's rings and the Great Orion Nebula (M42). The English Astronomer Royal Nevil Maskelyne visited the Herschels while they were at Walcot (which they left on 29 September 1777). By 1779, Herschel had also made the acquaintance of Sir William Watson, who invited him to join the Bath Philosophical Society. Herschel became an active member, and through Watson would greatly enlarge his circle of contacts. A few years later, in 1785, Herschel was elected an international member of the American Philosophical Society in Philadelphia.
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