Madrid in 1900This wistful painting of a Spanish square on a rainy day, by Enrique Martínez Cubells y Ruiz (1874–1917), includes a revealing commentary on how scientific discoveries transformed urban life. Coachmen wait atop their expensive hackney cabs for a wealthy clientele, while modern electric streetcars that carry the masses converge on the square from all directions. In this way the development of electricity brought improved urban transportation and enabled the city to expand to the suburbs. (Museo Muncipal, Madrid, Spain/Giraudon/The Bridgeman Art Library)