Then come pastoral life, Jabal with his tent, his flock and dog; Jubal, the maker of stringed and wind instruments; Tubal Cain, the first worker in metal; the first vintage, represented by the story of Noah. On the southern side comes first Astronomy, represented by either Zoroaster or Ptolemy. Then follow Building, Pottery, Riding, Weaving, and (according to Ruskin) the Giving of Law. Lastly Daedalus, symbolising, according to Ruskin, "the conquest of the element of air"; or, more probably, here as in Dante (_Paradiso_ viii.), the typical mechanician. Next, on the eastern side, comes Rowing, symbolising, according to Ruskin, "the conquest of the sea"--very possibly intended for Jason and the Argo, a type adopted in several places by Dante. The next relief, "the conquest of the earth," probably represents the slaying of Antæus by Hercules, and symbolises the "beneficent strength of civilisation, crushing the savageness of inhumanity." Giotto uses his mythology much as Dante does--as something only a little less sacred, and of barely less authority than theology--and the conquest of Antæus by Hercules was a solemn subject with Dante too; besides a reference in the _Inferno_, he mentions it twice in the _De Monarchia_ as a special revelation of God's judgment by way of ordeal, and touches upon it again in the _Convivio, secondo le testimonianze delle scritture_. Here Hercules immediately follows the "conquest of the sea," as having, by his columns, set sacred limits to warn men that they must pass no further (_Inferno_ xxvi.). Brutality being thus overthrown, we are shown agriculture and trade,--represented by a splendid team of ploughing bulls and a horse-chariot, respectively. Then, over the door of the tower, the Lamb with the symbol of Resurrection, perhaps, as Ruskin thinks, to "express the law of Sacrifice and door of ascent to Heaven"; or, perhaps, merely as being the emblem of the great Guild of wool merchants, the Arte della Lana, who had charge of the cathedral works. Then follow the representations of the arts, commencing with the relief at the corner: Geometry, regarded as the foundation of the others to follow, as being _senza macula d'errore e certissima_. Turning the corner, the first and second, on the northern side, represent Sculpture and Painting, and were possibly carved by Giotto himself. The remaining five are all later, and from the hand of Luca della Robbia, who perhaps worked from designs left by Giotto--Grammar, which may be taken to represent Literature in general, Arithmetic, the science of numbers (in its great mediæval sense), Dialectics; closing with Music, in some respects the most beautiful of the series, symbolised in Orpheus charming beasts and birds by his strains, and Harmony. "Harmony of song," writes Ruskin, "in the full power of it, meaning perfect education in all art of the Muses and of civilised life; the mystery of its concord is taken for the symbol of that of a