Page 612 - 89 history of astronomy_opt

regular intervals of fifty-two days the lines
ˆ
in the spectrum of I of the Great Bear are
duplicated, indicating a relative velocity, equal
to one hundred miles a second, of two com-
ponents revolving round each other, of which
that apparently single star must be com-
posed.
It would be interesting, no doubt, to fol-
low in detail the accumulating knowledge
612