person" of an earthquake, he found it interesting enough to publish in Transactions of the Geological Society of London in 1823. One of her observations had been that of large areas of land rising from the sea, and in 1830 that observation was included in the groundbreaking work The Principles of Geology by the geologist Charles Lyell, as evidence in support of his theory that mountains were formed by volcanoes and earthquakes. Four years later the president of the Society, George Bellas Greenough, decided to attack Lyell's theories. But instead of attacking Lyell directly, he did it by publicly ridiculing Maria Callcott's observations. Maria Callcott, however, was not someone who accepted ridicule. Her husband and her brother offered to duel Greenough, but she said, according to her nephew John Callcott Horsley, "Be quiet, both of you, I am quite capable of fighting my own battles, and intend to do it". She went on to publish a crushing reply to Greenough, and was shortly thereafter backed by none other than Charles Darwin, who had observed the same land rising during Chile's earthquake in 1835, aboard the Beagle. In 1837 Augustus Callcott was knighted and his wife became known as Lady Callcott. Shortly afterwards her health began to deteriorate, and in 1842 she died aged 57. She continued to write until the very end, and her last book was A Scripture Herbal, an illustrated collection of tidbits and anecdotes about plants and trees mentioned in the Bible, which was published the same year she died. Augustus Callcott died two years later, at the age of 65, having been made Surveyor of the Queen's Pictures in 1843. Honoured in 2008 In recognition of her services to Chile, as being one of the first persons to write about the young nation in the English language, the Chilean government paid for the restoration of Maria and Augustus Callcott's joint grave in Kensal Green Cemetery in London in 2008. The restoration was finalised with a commemorative plaque, unveiled by the Chilean ambassador to the United Kingdom, Rafael Moreno, at a ceremony on 4 September 2008. The plaque names Maria Callcott "a friend of the nation of Chile". Works As Maria Graham:Journal of a residence in India (1812) – translated into French 1818Memoirs of the war of the French in Spain (by Albert Jean Rocca) – translation from French (1816)Letters on India, with etchings and a map