Electric light by the first practical electric arc light in 1806. By the 1870s, Davy's arc lamp had been successfully commercialized, and was used to light many public spaces. The development of a steadily glowing filament suitable for interior lighting took longer, but by the early twentieth century inventors had successfully developed options, replacing the arc light with incandescents. The energy efficiency of electric lighting has increased radically since the first demonstration of arc lamps and the incandescent light bulb of the 19th century. Modern electric light sources come in a profusion of types and sizes adapted to many applications. Most modern
Royal Geological Society of Ireland 1862). The Dublin clergyman Maxwell Henry Close read a paper before the society in 1866, on the "General Glaciation of Ireland", a masterly description of the effects of glaciation, and of the evidence in favor of the action of land-ice. He became president of the society in 1878. The society gained royal patronage and a change in title in 1864. The Society did not admit women members. Throughout the latter decades of the century, for several reasons, membership slowly declined and the society was wound up in 1894. Royal Geological Society of Ireland The Royal Geological Society of Ireland traces