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 where a very famous temporary star appeared in that year. It was bright enough at one time to be seen in full sunshine. The star η is sixteen light years distant.

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.