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now know that this occurred because, owing to the motion of the planet in its orbit, they were seen edge-on, and are then so thin as to be invisible in a telescope as imperfect as Galileo's. But the disappearance was a source of great embarrassment to the Tuscan philosopher, who is said to have feared that he had been the victim of some illusion on the subject, and ceased to observe Saturn. He was then growing old, and left to others the task of continuing his observations. Of course the handles soon reappeared, but there was no way of learning what they were. After more than forty years the riddle was solved by Huyghens, the great Dutch astronomer and physicist, who announced that the planet was surrounded by a thin plane ring, nowhere touching it, and inclined to the ecliptic.

Besides his rings, Saturn is surrounded by a retinue of eight satellites—a greater number than any other planet. The existence of a ninth has been suspected, but awaits confirmation. They are very unequal in size and distance from the planet. One, Titan, may be seen with a small telescope; the faintest, only in very powerful ones.

Titan was discovered by Huyghens just as he had made out the true nature of the rings. And hereby hangs a little tale which has only recently come out through the publication of Huyghens's correspondence. Following a practice of the time, the astronomer sought to secure priority for his discovery without making it known, by concealing it in an anagram, a collection of letters which, when properly arranged, would inform the