=1. The Stars.= The stars are distant suns, varying greatly in remoteness, in magnitude, and in condition. Many of them are much smaller than our sun, and many others are as much larger. They vary, likewise in age, or state of development. Some are relatively young, others in a middle stage, and still others in a condition that may be called solar decrepitude. These proofs of evolution among the stars, the knowledge of which we owe mainly to spectroscopic analysis, serve to establish more firmly the conclusion, to which the simple aspect of the heavens first leads us, that the universe is a connected system, governed everywhere by similar laws and consisting of like materials.