Earlier lamps were made out of stone or seashells. The shape was like a circular bowl with a protruding beak. Later, they were replaced by earthen and metal lamps. In the epics "Ramayana" and "Mahabharata", there are references to gold and silver lamps as well. The simple shape evolved and the lamps were created in the shapes of the ('fish'), ('tortoise') and other incarnations of god Vishnu. Lamps were also created in the shape of the many emblems of gods, like conch shells or lotuses. Birds such as swans, peacocks, or parrots, and animals like snakes, lions, elephants and horses were also favorites when decorating a lamp. For lighting multiple lamps, wooden and stone ('towers of light') were created.