Sarah Siddons as the Tragic Muse paintings of Melpoméne, she is represented with a tragic mask and also often holds in her other hand a knife or club. In Greek mythology, she is the daughter of Zeus and Mnemosyne, who had eight other daughters, Melpoméne's sisters and the eight other muses are: Calliope, muse of epic poetry; Clio, muse of history; Euterpe, muse of flute playing; Terpsichore, muse of dancing; Erato, muse of erotic poetry; Thalia muse of comedy; Polyhymnia, muse of hymns; and Urania, muse of astronomy. Reynolds was inspired not only by Sarah Siddons' extreme talent to embody the tragic heroine in Macbeth, but
Ancient Greek units of measurement Ancient Greek units of measurement Ancient Greek units of measurement varied according to location and epoch. Systems of ancient weights and measures evolved as needs changed; Solon and other lawgivers also reformed them "en bloc". Some units of measurement were found to be convenient for trade within the Mediterranean region and these units became increasingly common to different city states. The calibration and use of measuring devices became more sophisticated. By about 500 BC, Athens had a central depository of official weights and measures, the "Tholos", where merchants were required to test their measuring devices against official standards. Some Greek