Seven-foot Reflecting Telescope

The full-sized replica in brass and rosewood of Herschel’s seven-foot, reflecting telescope is our most iconic object and is on display in the Reception Room on the Ground Floor.  It was made by Michael Tabb (William Herschel Society) and is fully functional.  Its mirrors are made from polished speculum metals cast in horse dung – the very method used by Herschel himself!

Using his seven-foot reflecting telescope in the back garden of 19 New King Street – the home of the Herschel Museum of Astronomy – Herschel, an amateur astronomer, discovered what we now know as the planet Uranus between 10pm and 11pm on the night of 13 March 1781.  This was the first planet to be discovered since the days of the Ancient Greek astronomers.  Herschel’s discovery – made from the back garden of a modest Bath terrace – thus doubled the size of the known universe.

The new planet was initially called Georgium Sidus in honour of King George III, fellow Hanoverian and Patron of William Herschel.  It was later decided to call Herschel’s discovery ‘Uranus’, however, in the tradition of naming celestial objects after classical gods.  The name ‘Uranus’ was championed by Johann Elert Bode, a German astronomer.  As Saturn was the father of Jupiter, Bode argued, the new planet should be named after the father of Saturn.  Bode’s proposal was officially adopted in 1850.


Brass Drum Orrery (c. 1782)

Made by the celebrated instrument-maker George Adam, the orrery works on a clockwork mechanism and shows how the planets move around the sun.  The longest of the orrery’s arms supports the planet Uranus, with two of its moons, on the edge of the solar system.

Orreries, such as this elegant example, were often made as playthings for wealthy gentlemen to display in their homes to guests.  Scientists such as William Herschel, however, used them as tools in practical demonstrations to help illustrate complex astronomical concepts to a lay audience.

The brass drum orrery is one of a collection of contemporary astronomical instruments on loan from the Science Museum in London.


William Herschel’s Travel Diary

Part of the Herschel Family Archive, this leather-bound notebook is a unique record of William Herschel’s journey to Scotland and the north of England in the 1790s.  Among the observations are several sketches of machinery and instruments that he saw in factories, foundries, and workshops.


Mirror polishing machine

The polishing machine in William Herschel’s workshop is a mechanical device he invented to make the process of grinding and polishing his telescopic mirrors less laborious.  It has an inbuilt parabolic curve, which is an essential element of the finishing process.

This is an exact copy of the original (now in the Science Museum, London).  Visitors are encouraged to turn the handle to see how it works.


Dress worn by Caroline Herschel

From the Herschel Family Archive, this simple muslin dress would have been worn by Caroline when she was about fifty.  Several patches and repairs are visible.

Perhaps the most striking thing about the dress is its size, which is rather small for a mature woman.  Ironically the celebrated ‘First Lady of Astronomy’, who soared into space through her telescope, remained solidly earthbound, never growing taller than 4’3”.  This was a legacy of childhood neglect at the hands of her mother and eldest brother, as well as due to the effects of smallpox and typhus.


Caroline Herschel’s Visitors’ Book

This vellum-bound volume was compiled by Caroline Herschel from the mid-1780s when she and her brother were living in Datchet near Windsor.  Written in Caroline’s own hand, it lists over a hundred names of people who came to Observatory House – often with the King and Queen, attended by members of Court – to look through William’s telescopes.  Scientists, writers, artists, politicians and foreign royalty all feature.  Lord Byron, Joseph Haydn, and Fanny Burney are listed among the guests.  (A digital copy of the book is also available for visitors in the Reception Room.)

The Visitors’ Book is on display courtesy of Dr and Mrs A. Koester.

Margaret Bryan

Miniature portrait group of Margaret Bryan and her daughters

This painting by miniaturist Samuel Shelley is on display in the Drawing Room and depicts Margaret Bryan and her two daughters with a collection of astronomical instruments.  A contemporary of Caroline Herschel, Mrs Bryan ran a seminary for young ladies and had a passion for astronomy.

In 1797, Bryan wrote a book of essays titled A Compendius System of Astronomy in a Course of Familiar Lectures.  A second edition of this publication is also on view in the Drawing Room.  Representing the author as both an astronomer and a mother, this family portrait was used for the engraved frontispiece of Mrs Bryan’s book.

This miniature and the copy of Mrs Bryan’s book were purchased through grant aid from The PRISM Fund and the Royal Astronomical Society.