of the great comets. The comet was also observed by Thomas Glanville Taylor at the Madras Observatory. Railway Journal In 1835 Herapath became editor of The Railway Magazine, which underwent four changes of name during the boom years of railways to become Herapath's Railway Journal in January 1894. It is now published as Railway Gazette International, and is not to be confused with The Railway Magazine which commenced publication in 1897. This gave him some limited opportunity to publish his scientific ideas. In 1836, he published a calculation of the mean molecular speed in a gas based on his kinetic theory and hence the speed of sound. Joule reproduced his results but is usually incorrectly credited as the originator. The name changes were - Railway magazine May 1835-Feb. 1836 Railway magazine and annals of science Mar. 1836-Aug. 1839 Railway magazine and steam navigation journal Mar.-Aug. 1839 Railway magazine and commercial journal Aug. 17, 1839-Dec. 1840 Herapath's railway magazine, commercial journal, and scientific review Jan. 1841-Dec. 1842 Herapath's railway and commercial journal Jan. 1843-Dec. 1845 The editions from 1839 to 1895 can be viewed in the National Archives and several issues are also available as e-books, e.g. 1837, 1836-1839 and several in Google books. Later work He revised his theories in the 1840s, largely based on the experimental work of Thomas Graham and Henri Victor Regnault. 1847: Mathematical Physics; or, the Mathematical Principles of Natural Philosophy, the causes of heat, gaseous elasticity, gravitation, and other great phenomena of nature, Whittaker and company via HathiTrust Herapath died at Catford Bridge, Lewisham on 24 February 1868 and was buried at West Norwood Cemetery. See also List of railroad-related periodicals John James Waterston References External links Dave Levermore (2001) Neglected Pioneers: John Herapath from University of Maryland 1790 births 1868 deaths English physicists 19th-century British astronomers Discoverers of comets Burials at West Norwood Cemetery