This brings us again to the consideration of those marvelous appendages,
and to the statement of facts about them which we have not yet recalled.
If the reader will take a ball three inches in diameter to represent the
globe of Saturn, and, out of the center of a circular piece of
writing-paper seven inches in diameter, will cut a round hole three and
three quarter inches across, and will then place the ball in the middle
of the hole in the paper, he will have a very fair representation of the
relative proportions of Saturn and its rings. To represent the main gap
or division in the rings he might draw, a little more than three eighths
of an inch from the outer edge of the paper disk, a pencil line about a
sixteenth of an inch broad.
Perhaps the most striking fact that becomes conspicuous in making such a
model of the Saturnian system is the exceeding thinness of the rings as
compared with their enormous extent. They are about 170,000 miles across
from outer edge to outer edge, and about 38,000 miles broad from outer
edge to inner edge--including the gauze ring presently to be
mentioned--yet their thickness probably does not surpass one hundred
miles! In fact, the sheet of paper in our imaginary model is several
times too thick to represent the true relative thickness of Saturn's
rings.
Several narrow gaps in the rings have been detected from time to time,
but there is only one such gap that is always clearly to be seen, the
one already mentioned, situated about 10,000 miles from the outer edge
and about 1,600 miles in width.
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