, , - , . - , (Frank, Lang, 1959; Lang, 1964).

(Van der Veen, 1913; Williams, 1932; , 1955; Frank, Puttick, Wilks, 1958; Frank, Lang, 1959; Lang, 1959; , 1963 .). : 10 , ~ 100 . (Tolansky, 1960), 0,3 2,0 . , {332} ( {111} 10′-15′). , . . , , {332}.