Location.—A line drawn from δ Ursæ Majoris, through Polaris, strikes α Cassiopeiæ. It is situated the same distance from Polaris as Ursa Major, and about midway between Polaris and the zenith in the Milky Way. Cassiopeia is characterized by a zigzag row of stars which form a rude "W," but in mid-autumn, to an observer facing north, the "W" appears more like an "M," and is almost overhead. Note the spot marked 1572. This is wher
Caph is equidistant from the Pole, and exactly opposite the star Megres in Ursa Major; with α Andromedæ and γ Pegasi it marks the equinoctial colure. These stars are known as "The Three Guides."
The chair can be readily traced out; β, α, and γ mark three of the four corners of the back, and δ and ε, one of the front legs. The word "Bagdei," made up of the letters for the principal stars, assists the memory.
The stars γ and β are pointer stars to a fifth-magnitude star the lucida of the asterism Lacerta, the lizard about 15° from β.
Cassiopeia makes an excellent illuminated clock. When β is above Polaris it is noon, when it is in the west at right angles to its first position it is 6 p.m. At midnight it is on the northern horizon, and at 6 p.m. it is due east.
This is sidereal time which agrees with mean time on March 22d, and gains on the latter at the rate of two hours a month.