David Thomas Ansted, an English physicist, born in London in 1814. He was educated at Cambridge, and has been professor of geology at King's college, London, and the college of civil engineers at Putney. During the last 25 years he has been principally engaged on works illustrating the application of geology to engineering and mining. Besides several treatises on geology and related subjects, he has published "Scenery, Science, and Art" (1854), "The Channel Islands" (1862), "Correlation of the Natural History Sciences" (1863), "The Ionian Islands" (1863), and "Physical Geography" (4th ed., 1870). He has also contributed largely to the scientific reviews; and while vice president of the geological society he edited several volumes of their quarterly review. As a consulting engineer he has a high reputation.