the Rhine. He made significant contributions to the study of loess material and loess deposits and published what is probably the first illustration of a loess section. He also produced the first map of the Siebengebirge region of the Rhineland. In 1828 he returned to Edinburgh to take charge of his ailing father's company. In 1829, on the death of his father, he took full charge of the company, and continued in this role until 1833. In 1833 he was appointed one of the commissioners to inquire into the employment of children in the factories of Great Britain, and he was subsequently selected as one of the inspectors. He held this post for 26 years and during this time arguably did more to improve the working condition of women and children in the mills of north England than any other person in the 19th-century and for which he was praised by Karl Marx in Das Kapital. In later years he devoted much attention to the geological history of the alluvial lands of Egypt; and in 1843 he published his Life of his brother Francis. Family Horner married Anna Susanna Lloyd, daughter of Gamaliel Lloyd. They had six daughters, who were all educated to a high standard for the age. The eldest sister, Mary Elizabeth, married Sir Charles Lyell, author of The Principles of Geology in 1832. Her younger sister Katharine married Lyell's younger brother Henry in 1848, and later edited The Life, Letters and Journals of Sir Charles Lyell. A third daughter, Frances, married Charles Bunbury, a noted paleobotanist. A fourth daughter, Leonora, married Georg Heinrich Pertz, a historian and archivist; one of their children was Dorothea Pertz and through this connection Horner was the step-great-great-grandfather of astronomer and astrophysicist Cecilia Payne-Gaposchkin. Two other daughters, Susan and Joanna, were known in their day as the authors of a book on walking tours of Florence, Italy. Freemasonry He was Initiated into Scottish Freemasonry in 1803 in Lodge Canongate Kilwinning, No.2. He was also an honorary member of Lodge Kirknewton and Ratho, No.85, this also being conferred in 1803. Death He died in Montagu Square in London on 5 March 1864. References Karl Marx "Das Kapital, Volume I" London 1867: "He rendered undying service to the English working-class." (ch. 9) Memoir of Leonard Horner, by Katherine M Lyell (1890) (privately printed). Vol. 1 Vol. 2 Charles Darwin "Origin of Species" 1859 External