William Herschel and his sister Caroline Herschel were two of the foremost astronomers of their day. William is the discoverer of the planet Uranus, and he also discovered the existence of infrared light. Caroline was the first female astronomer to be actually paid for her work; she discovered eight comets during her career. They were born in Germany and moved to Bath to pursue music, before William turned to astronomy. They lived for many years in a terraced house in the city of Bath, UK, and it is in this house that the Museum celebrates their lives.
William was a talented musician and composer. He composed over 40 pieces of music including symphonies, concertos and other shorter pieces which were performed in and around Bath. He also taught Caroline to play various instruments, including the harp.
As William’s interests turned to astronomy, he needed a telescope. Being a resourceful engineer, he built his own. This is a replica of his 7-foot telescope (with a 6.2” diameter mirror) that he used to discover Uranus.
Pretty soon, William decided he wanted a bigger telescope. So he built this behemoth, with a 40-foot focal length and 48” mirror. This beast had a small cabin at the bottom for Caroline to sit in, recording William’s observations which he communicated via a speaking tube. It took two more men to rotate the telescope into position. After a while the Herschels decided this was too much hassle and retreated to using a 20-foot telescope instead. However he did discover two moons of Saturn with this big one.
In order to make his own telescopes, Herschel needed to make his own mirrors. The whole basement of their house was given over to forging, grinding and polishing large mirrors. Other people recognized the quality of his work and were purchasing mirrors and telescopes from him, so he was kept busy. The image below shows his forge, a mechanical mirror polishing machine, and two of the mirrors he made.
There are, of course, many other interesting instruments and devices shown in the Museum. You know I’m going to start with this Astrolabe 😉 Look at it, the rete is covered in leaves and birds, and there are two elephant heads at the top. This example is from Jaipur, India; it was commissioned in 1836 by Maharaja Manna Lala. It is written in Sanskrit. Honestly it doesn’t have a lot to do with the Herschels but it does put their work in context with what had gone before. I am glad to see it though; it’s gorgeous.
We have items here from the oldest to the newest(-ish) examples of technology. On the left is a Gregorian reflector telescope made by James Short in the late 1700s. These were the best telescopes available in their day. (Herschel’s came afterwards and were better still). On the right we have an electronic camera of the same type that was launched on the Voyager 2 probe. (I’m going out on a limb here; it seems likely that Voyager 1 would have carried a similar camera, so maybe the “Pale Blue Dot” photo was taken with one of these)
These are cute; they are Pocket Globes from the 18th Century. One has terrestrial features and the other is celestial. The brass cage would fit around the globe for reading latitude, longitude and declination. They were more decorative than functional, but useful as a teaching aid.
A quick shout out to John Russell; whose Moon globes were popular enough that I have now seen two of them! (The other is on my Oxford page).
Of course, no self-respecting household would be without an Orrery featuring the newly-discovered planet Uranus.
And here is a Copernican armillary sphere from 1810, with Uranus on the outer edge. It was still being referred to as “Herschel’s Planet” after a brief period of being named “George’s Star” after the British king. Eventually in 1850 the name Uranus was officially adopted, following Greek mythology naming conventions.
This is the back of the house where the Herschels would have made their observations. You can see it’s just an ordinary terraced house. The garden is not large, maybe 20×40 feet. Of course light pollution would not have been anything like as bad as it is today. It’s still impressive that they were able to discover so much from here.
And here’s a close up of that plaque on the wall.
I’ve left out a lot here – you need to go and visit this most excellent museum! It is really worth the time to track down; it’s fairly central downtown in Bath, you can walk from the city center to the house in ten minutes. https://herschelmuseum.org.uk