What has gone before, will, I think, have served abundantly to establish the position with which I started, namely, that comets occupy (and deservedly so) the front rank amongst those astronomical objects in which, on occasions, the general public takes an interest.
I have thus completed, so far as the space at my disposal has permitted, a popular descriptive Survey of the Solar System. Those who have perused the preceding pages, however slight may have been their previous acquaintance with the Science of Astronomy taken as a whole, will have no difficulty in realising that what I have said bears but a small proportion to what I have left unsaid. They will equally, I hope, be able to see, without indeed the necessity of a suggestion, that all those wondrous orbs which we call the planets could neither have come into existence nor have been maintained in their allotted places for so many thousands of years, except as the result of Design emanating from an All-powerful Creator.
[1]The remark in the text applies to all the major planets and to a large number of the minor planets, but certain of the minor planets travel in orbits which are considerably inclined to the ecliptic, and therefore to all the other planets.
[2]Given in full in my _Handbook of Astronomy_, 4th ed., vol. i., p. 26.
[3]“_Recollections of Past Life_,” 2nd ed., p. 305.
[4]For some information respecting these Secchi “Types” of Stars, see my “_Story of the Stars_,” 2nd ed., p. 140.
[5]The circle and the ellipse are what are called “closed” curves.
[6]It is not a little singular that the Chinese in bygone centuries have often alluded to comets under the name of vapours; _e.g._, the comet of 1618 is recorded as having been “a white vapour 20 cubits long.”
Name. Sidereal Mean Diameter. Surface. Volume. Mass. Density. Axial Force of Velocity period. distance Miles. Earth=1. Earth=1. Earth=1. Earth=1. Rotation. gravity. in orbit. from d. h. m. Fall: Miles per Sun. Ft. in 1 hour Millions sec. of miles. SUN ..... ..... 866,200 11,946 1,305,000 332,000 0.25 25 7 48 461 h. m. s. MERCURY 88 days. 36 3,008 0.144 0.055 0.066 1.26 24 5 30 7 107,000 VENUS 225 ″ 67 7,480 0.891 0.841 0.782 0.92 23 21 23 14 78,000 EARTH 365 ″ 93 7,926 1.000 1.000 1.000 1.00 23 56 4 16 66,000 MARS 687 ″ 141 5,000 0.398 0.251 0.107 0.45 24 37 23 4 53,000 Minor Planets Eros (433) 1.76 ..... 18 Eros is the nearest to the Sun of the Minor Planets, part years. of its orbit falling between the Earth and Mars. Vesta (4) 3.6 ″ 219 214 Vesta is the largest of the Minor Planets. Thule (279) 8.8 ″ 396 ..... Thule is the most distant from the Sun of the Minor Planets. JUPITER 11.8 ″ 483 88,439 124 1,389 317 0.23 9 55 21 41 29,000 SATURN 29.4 ″ 886 75,036 89 848 94 0.11 10 29 17 18 21,000 URANUS 84.0 ″ 1782 30,875 15 59 14 0.25 ? 13 15,000 NEPTUNE 164.6 ″ 2792 37,205 21 103 17 0.17 ? 12 12,000