Leonard Horner FRSE FRS FGS (17 January 1785 – 5 March 1864) was a Scottish merchant, geologist and educational reformer. He was the younger brother of Francis Horner. Horner was a founder of the School of Arts of Edinburgh, now Heriot-Watt University and one of the founders of the Edinburgh Academy. A 'radical educational reformer' he was involved in the establishment of University College School. As a commissioner on the Royal Commission on the Employment of Children in Factories, Horner arguably did more to improve the working conditions of women and children in North England than any other person in the 19th century. Early life and education His father, John Horner, was a linen merchant in Edinburgh, and partner in the firm of Inglis & Horner. Leonard, the third and youngest son, attended the High School and entered the University of Edinburgh in 1799. There in the course of the next four years he studied chemistry and mineralogy, and gained a love of geology from Playfairs Illustrations of the Huttonian Theory. At the age of nineteen he became a partner in a branch of his father's business, and went to London. Career In 1808 he joined the newly formed Geological Society of London and two years later was elected one of the secretaries. Throughout his long life he was ardently devoted to the welfare of the society; he was elected president in 1846 and again in 1860. In 1811 he read his first paper On the Mineralogy of the Malvern Hills (Trans. Geol. Soc. vol. i.) and subsequently communicated other papers on the Brine-springs at Droitwich, and the Geology of the S.W. part of Somersetshire. He was elected fellow of the Royal Society in 1813. In 1815 he returned to Edinburgh to take personal superintendence of his business, and while there (1821) he was instrumental in founding the Edinburgh School of Arts 101 the instruction of mechanics, and he was one of the founders of the Edinburgh Academy. In 1827 he was invited to London to become warden of London University (now University College London), an office which he held for four years; he then resided at Bonn for two years and pursued the study of minerals and rocks, communicating to the Geological Society on his return a paper on the Geology of the Environs of Bonn, and another On the Quantity of Solid Matter suspended in the Water of