Horace Walpole turns to the letters and argues that: Walpole's numerous letters are often used as a historical resource. In one, dating from 28 January 1754, he coined the word serendipity which he said was derived from a "silly fairy tale" he had read, "The Three Princes of Serendip". The oft-quoted epigram, "This world is a comedy to those that think, a tragedy to those that feel", is from a letter of Walpole's to Anne, Countess of Ossory, on 16 August 1776. The original, fuller version appeared in a letter to Sir Horace Mann on 31 December 1769: "I have often said,
For the Term of His Natural Life relatively minor crimes, and graphically describes the conditions the convicts experienced. The novel was based on research by the author as well as a visit to the penal settlement of Port Arthur, Tasmania. Structurally, "For the Term of His Natural Life" is made up of a series of semi-fictionalised accounts of actual events during the convict era, loosely bound together with the tragic story of its hero. Most of the incidents and many of the individual characters are easily identifiable from historical sources including Marcus Clarke's own non-fiction work "Old Tales of a Young Country". Typically of Victorian-era convict novels,