Śailādi said: The perpetual pit in. the altar for the sacred fire of sacrifice shall have three girdles round it. The outer girdle is four Aṅgulas in width, the middle one three Aṅgulas, the inner one two. The width of the Kuṇḍa shall be one cubit. The central portion where the sacrificial offerings are poured shall be about nine inches. The Yoni shall be like the leaf of Aśvattha in shape and formed higher than the girdle.