Stránka:roll 1910.djvu/122

io6 BOY SCOUTS OF AMERICA from the bottom back star of the Dipper (Gamma) through the outer rim star of the same (Alpha), about two and one-half Dipper-lengths, and it ends at Algol, or a line from the last star of the Dipper-handle through the Pole-star, and as far on the other side, ends also at Algol. This is a wonderful, variable star that changes from about second to about fourth magnitude in less than three days. For two and one-half days it is constant, then it begins to fade, and in two and one-half hours is down to fourth magnitude; remains so for about fifteen minutes; then in three and one-half hours is restored to second magnitude. This change is supposed to be caused by a dark planet passing over it. It was formerly red; now white (Gore). MIZAR (My'-zar). Zeta of Ursa Major. This is the middle star of the Dipper-handle, the one that marks the curve. Close above Mizar is a very small star which can be seen by very keen eyes unaided by glasses. This little star is Alcor. These two are called the Horse and Rider, or, among the In- dians, the Squaw and Pappoose.