Recreations in Astronomy eBook

This eBook from the Gutenberg Project consists of approximately 235 pages of information about Recreations in Astronomy.

Recreations in Astronomy eBook

This eBook from the Gutenberg Project consists of approximately 235 pages of information about Recreations in Astronomy.

Huyghens, in March, 1655, solved the problem of the triform appearance of Saturn.  He saw them as handles on the two sides.  In a year they had disappeared, and the planet was as round as it seemed to Galileo in 1612.  He did not, however, despair; and in October, [Page 170] 1656, he was rewarded by seeing them appear again.  He wrote of Saturn, “It is girdled by a thin plain ring, nowhere touching, inclined to the ecliptic.”

Since that time discoveries have succeeded one another rapidly.  “We have seen by degrees a ring evolved out of a triform planet, and the great division of the ring and the irregularities on it brought to light.  Enceladus, and coy Mimas, faintest of twinklers, are caught by Herschel’s giant mirrors.  And he, too, first of men, realizes the wonderful tenuity of the ring, along which he saw those satellites travelling like pearls strung on a silver thread.  Then Bond comes on the field, and furnishes evidence to show that we must multiply the number of separate rings we know not how many fold.  And here we reach the golden age of Saturnian discovery, when Bond, with the giant refractor of Cambridge, and Dawes, with his 6-1/3-inch Munich glass, first beheld that wonderful dark semi-transparent ring, which still remains one of the wonders of our system.  But the end is not yet:  on the southern surface of the ring, ere summer fades into autumn, Otto Struve in turn comes upon the field, detects, as Dawes had previously done, a division even in the dark ring, and measures it, while it is invisible to Lassell’s mirror—­a proof, if one were needed, of the enormous superiority possessed by refractors in such inquiries.  Then we approach 1861, when the ring plane again passes through the earth, and Struve and Wray observe curious nebulous appearances."[*]

[Footnote *:  Lockyer.]

Our opportunities for seeing Saturn vary greatly.  As the earth at one part of its orbit presents its south pole [Page 171] to the sun, then its equator, then the north pole, so Saturn; and we, in the direction of the sun, see the south side of the rings inclined at an angle of 27 deg.; next the edge of the rings, like a fine thread of light; then the north side at a similar inclination.  On February 7th, 1878, Saturn was between Aquarius and Pisces, with the edge of the ring to the sun.  In 1885, the planet being in Taurus, the south side of the rings will be seen at the greatest advantage.  From 1881 till 1885 all circumstances will combine to give most favorable studies of Saturn.  Meanwhile study the picture of it.  The outer ring is narrow, dark, showing hints of another division, sometimes more evident than at others, as if it were in a state of flux.  The inner, or second, ring is much brighter, especially on the outer edge, and shading off to the dusky edge next to the planet.  There is no sign of division into a third dusky innermost ring, as was plainly seen by Bond.  This, too, may be in a state of flux.

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Recreations in Astronomy from Project Gutenberg. Public domain.