87. Q. Give the names of five double or multiple stars. A. Polaris, Sirius, Procyon, Castor, and sixty-one Cygni.
88. Q. What is said of the color of stars? A. They are of various colors.
89. Q. Name five stars each having a different color. A. Sirius, white; Capella, yellow; Castor, green; Aldebaran, red; and Lyra, blue.
90. Q. What are clusters of stars? A. In various parts of the heavens there are small globular well-defined clusters, and clusters very irregular in form marked with sprays of stars.
91. Q. How do these clusters appear to the eye, or through a small telescope? A. As little cloudlets of hazy light.
92. Q. What is the new and better substantiated possibility of thought concerning these clusters? A. That they belong to our system, and hence that the stars must be small and young.
93. Q. What does the spectroscope show that some of these little cloudlets of hazy light called nebulæ are? A. That they are not stars in any sense, but masses of glowing gas.
94. Q. What are some of the shapes of nebulæ? A. Nebulæ are of all conceivable shapes—circular, annular, oval, lenticular, conical, spiral, snake-like, looped, and nameless.
95. Q. Of how many stars has a variation in magnitude been well ascertained? A. One hundred and forty-three.
96. Q. What are temporary stars? A. Those that shine awhile and then disappear.