_Early Observations._—The appearance of Saturn offered a considerable difficulty to observers soon after the invention of the telescope. Galilei became greatly perplexed. He saw the planet, not as a circular globe like Jupiter, but distinctly elongated in shape, and conceived the appearance to be due to a central globe with smaller spheres hanging on the sides! He continued his observations, without, however, arriving at the solution of the mystery, until the malformation began to disappear; and in 1612 he was astonished to find the disk spherical. In his surprise, he asked—“Were the appearances indeed illusion and fraud, with which the glasses have so long deceived me, as well as many others to whom I have shown them?... The shortness of the time, the unexpected nature of the event, the weakness of my understanding, and the fear of being mistaken, have greatly confounded me.” Gassendi, in 1633, also announced that Saturn appeared to him to be closely attended by two globes of the same colour as the planet. Riccioli alleged that the planet was surrounded by a thin, plain, elliptic ring, connected with the sphere by two arms. None of Galilei’s contemporaries possessed the instrumental means to extricate him from his doubts; and it remained for Huygens, in 1654 (twelve years after the death of Galilei), to discover that Saturn “is surrounded by a slender flat ring, which in no part coheres with the body of the planet, and is inclined to the ecliptic”[36]. The same observer showed that the disappearance which had so puzzled Galilei arose from the varying inclination in the ring: at times it would become invisible, when presenting its narrow edge to the Earth, and this actually occurred again in 1671, as Huygens had predicted. In 1676 Cassini detected a belt upon the planet, and also a dark division in the ring. Dr. Smith’s ‘Optics’ (1738) thus alludes to these discoveries:— [Illustration: Fig. 38. Saturn, as observed by Cassini in August 1676.] “In the year 1676, after Saturn had emerged from the Sun’s rays, Sig. Cassini saw him in the morning twilight with a darkish belt upon his globe, parallel to the long axis of his ring as usual. But what was most remarkable, the broad side of the ring was bisected right round by a dark elliptical line, dividing it, as it were, into two rings, of which the inner ring appeared brighter than the outer one, with nearly the like difference in brightness as between that of silver polished and unpolished—which, though never observed before, was seen many times after with tubes of 34 and 20 feet, and more evidently in the twilight or moonlight than in a darker sky.”