. , , , -, , , - -, .

(Mani, 1944; Nayar, 1941; Bishui, 1950; Przibram, 1953; Dyer, Matthews, 1958; Anderson, 1962; Clark, Thomson, 1964; , 1966 .).

, , 4150 5000 Ǻ (. 72, ), 8300 Ǻ. 4156, (4152 Ǻ t = 80 ). , . , 0,08 . , t = 80 (Clark et al