open door is closed. Tue Uses or ESCALATORS The escalator has greatly extended, chiefly by British warships. The debacle of the Heart,” Arch. Surg., 11, 550-77 (Oct. 1925); Peyton Rous and colla- borators, ‘‘ Chicken sarcomata,” Jour. Med., IQI1I, 13.397, Jour. Amer, Med. Assn, 1912, 59.1793, Jour. Exp. Zool, vol. 23 (i917); J- B.