In 1874 a very important, although not so obvious, service to variable-star astronomy was rendered by the Danish observer, _Hans Carl Fredrik Christian Schjellerup_ (1827-1887). He translated from Arabic into French the works of the Persian astronomer of a thousand years ago, Al-Sufi, and thus rendered his observations available to modern astronomers. Al-Sufi was a most accurate observer, and, by comparing his catalogue with those of modern observers, it can be found whether stars have changed in brilliance during the past thousand years. The study of variable stars has been pursued in recent years by many astronomers, both by means of photography and by the visual method. The most important names in the visual discovery of variables are Gustav Müller and _Paul Friedrich Ferdinand Kempf_ (born 1856) of Potsdam; _Alexander William Roberts_ of Lovedale, South Africa; Seth Carlo Chandler of Boston; Nils Christopher Dunér at Upsala; and _John Ellard Gore_ (born 1845) in Dublin. The researches of J. E. Gore are a brilliant example of how much may be done for astronomy by means of very moderate instruments. Born in 1845 at Athlone, in Connaught, he went to India in 1868 as engineer on the Sirhind Canal in the Punjab. While in India he erected his small telescopes on brick pillars, and took observations, many of them of stellar brilliance. In 1879 he returned to Ireland, and since then has devoted himself to astronomy with zeal and enthusiasm. His discoveries and investigations of variables have been made by means of the binocular. On December 13, 1885, he discovered a remarkable star in Orion, which was at first considered to be temporary, and called “Nova Orionis,” but was afterwards found to be a long-period variable star. Recently photography has come much to the front in the discovery of variable stars. Pickering at Harvard, and Wolf at Heidelberg, have particularly distinguished themselves in this branch, and the number of known variables is now very large, as every year brings fresh discoveries, mostly by aid of photography. Many of these newly-discovered variables are in star-clusters and nebulæ.