of infinite
space? The ratio is infinitely less than that which the water in a
single drop of dew bears to the water in the whole Atlantic Ocean.

APPENDIX.

ASTRONOMICAL QUANTITIES.

THE SUN.

The sun's mean distance from the earth is 92,900,000 miles; his diameter
is 866,000 miles; his mean density, as compared with water, is 1.4; his
ellipticity is insensible; he rotates on his axis in a period between 25
and 26 days.

THE MOON.

The moon's mean distance from the earth is 239,000 miles. The diameter
of the moon is 2,160 miles; and her mean density, as compared with
water, is 3.5. The time of a revolution around the earth is 27.322 days.

THE PLANETS.

___________________________________________________________________________
| |Distance from the Sun in | | Mean | |Density |
| | Millions of Miles. | Periodic |Diameter| Axial |compared|
| |-------------------------| Time | in | Rotation.| with |
| | Mean. | Least.|Greatest.| in Days. | Miles. | | Water. |
|-------+-------+-------+---------+----------+--------+----------+--------|
|Mercury| 36.0| 28.6| 43.3 | 87.969| 3,030 | (?) | 6.85(?)|
|Venus | 67.2| 66.6| 67.5 | 224.70 | 7,700 | (?) | 4.85 |
|Earth | 92.9| 91.1| 94.6 | 365.26 | 7,918 |23 56 4.09| 5.58 |
|Mars | 141 | 128 | 155 | 686.98 | 4,230 |24 37 22.7| 4.01 |
|Jupiter| 483 | 459 | 505 | 4,332.6 | 86,500 | 9 55 -- | 1.38 |
|Saturn | 886 | 834 | 936 |10,759 | 71,000 |10 14 -- | 0.72 |
|Uranus |1,782 |1,700 | 1,860 |30,687 | 31,900 | Unknown | 1.22 |
|Neptune|2,792 |2,760 | 2,810 |60,127 | 34,800 | Unknown | 1.11 |
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THE SATELLITES OF MARS.

Mean Distance from Periodic Time.
Name. Centre of Mars. hrs. mins. secs.

Phobos 5,800 miles 7 39 14
Deimos 14,500 miles 30 17 54

THE SATELLITES OF JUPITER.

Mean Distance from Periodic Time.
Name. Centre of Jupiter. days. hrs. mins. secs.

New Inner
Satellite
Barnard 112,500 miles 0 11 57 22
I. 261,000 miles 1 18 27 34
II. 415,000 miles 3 13 13 42
III. 664,000 miles 7 3 42 33
IV.