Herschel Letters
Dates: 1807-1875
This collection of nearly 10,900 letters, drafts, copies and notes is the largest repository of scientific correspondence from and to Sir John Herschel, leading figure of Victorian science.
by Louisiane Ferlier
Digital resources manager
Presented to the Royal Society in 1944 by the Rev. Sir John Frederick Charles Herschel (1869-1950), this collection of nearly 10,900 letters, drafts, copies and notes is the largest repository of scientific correspondence from and to the Victorian astronomer and man of science, Sir John Frederick William Herschel FRS (1792-1871).

Portrait of John Frederick William Herschel, by Christian Albrecht Jensen, 1843.
As a collection, the correspondence is organised into three main groups of documents.
HS/1 to HS/19 are manuscripts of the letters sent to Herschel and drafts and contemporary copies in his hand of his replies, which he preserved carefully in a dedicated cabinet. This includes correspondence with Mary Somerville (1780-1872), Charles Babbage FRS (1791-1871), Julia Margaret Cameron (1815-1879), Michael Faraday FRS (1791-1867), Augustus de Morgan (1806-1871) and Charles Darwin FRS (1809-1882).
HS/20 to HS/24 are copy books of Sir John Herschel’s outgoing letters gathered posthumously in 1873-1874 under the direction of one of his sons, the engineer and surveyor Colonel John Herschel FRS (1837-1921). The logistics of this copying exercise are also preserved in HS/28.
The copyists, Colonel John Herschel (who transcribed or checked the vast majority of letters), helped by his wife Mary Cornwallis Herschel (1829–1876) and one of his sisters, Francesca Herschel FRAS (1846-1932), initialed or signed their work.

HS/26 and HS/27 contains groups of letters relating to particular topics, such as Herschel's involvement in William Henry Fox Talbot's photography patent disputes, the administration of the British Association for the Advancement of Science, the Telescope Glass Committee, Sir John Herschel and Charles Babbage's disagreements with Sir Humphry Davy FRS (1778-1829) and Sir James South FRS (1785-1867) after Babbage's unsuccessful nomination for the position as Secretary of the Royal Society, and the construction of Babbage's "calculating machines", now known as the Difference Engine.

Draft letter, from Sir John Herschel to Henry Goulburn, dated at [London]
Creator: John Frederick William Herschel Reference number: HS/27/51
Sir John Herschel was one of the most significant figure of Victorian science. He was at the centre of a global network of correspondence, exchanging letters on a variety of scientific topics, with the foremost practitioners in each field.
His involvement in British bastions of science such as the Royal Society, the University of Cambridge, the Royal Astronomical Society and the British Association for the Advancement of Science, meant that he acted as a diplomat and administrator.
Beyond this, as a populariser of science, he was contacted by members of the public interested in his work, something the Darwin Correspondence Project also found in the letters of Charles Darwin.
Herschel's correspondence also goes beyond the scientific and highlights his engagement with the Victorian cultural world, through poetic and literary forays and a deep interest in photographic arts. We find letters from novelist Maria Edgeworth (1768-1849) poet Elizabeth Colling (1799-1879) writer Joanna Baillie (1762-1851) and photographer Julia Margaret Cameron, all of whom maintained close friendships with Herschel over decades.
His role as Master of the Mint placed him at the nexus of yet another set of more political and economic concerns, only a few years before the role was amalgamated with the office of Chancellor of the Exchequer.
The geography of the correspondence follows British imperial expansion of the nineteenth century. For example, many letters pertain to the Xhosa wars and South African politics due to Herschel’s presence and later continued interest in the Cape Colony; colonial scientific endeavours in India are also well represented. Letter exchanges with astronomers and mathematicians such as Adolphe Quetelet ForMemRS (1796-1874), and Heinrich Christian Schumacher ForMemRS (1780-1850) also show the importance of exchanges with continental scientists. Closer to home, the familial roots of the Herschels in Slough and then in Kent are obvious; these include a neighbourly dispute with Charles Dickens (1812-1870).
Map of volume 19 from the Sir John Herschel's correspondence
You can explore the correspondence in multiple ways:
Reveal the relationship between any two correspondents by using our Correspondence Explorer.
Use our search functionality to look for a specific topic.
Read more on Sir John Herschel and photography in Carolin Lange’s In Focus and a series of blogposts on the Royal Society website.
Explore the global dimension of the correspondence through our interactive map above.