| Name. | Designation. | Volume (Cubic Miles) at Density of Water. | Total Volume (Cubic Miles) at Density of Water. |
| Sun | — | — | 482,169,000,000,000,000 |
| Mercury | Planet | — | 92,735,000,000 |
| Venus | " | — | 1,131,960,000,000 |
| Earth | " | 1,471,169,000,000 | |
| Moon | Satellite | 18,141,236,000 | 1,489,310,236,000 |
| Mars | Planet | — | 160,728,460,000 |
| —— | Asteroids | One fourth of Earth | 367,792,000,000 |
| Jupiter | Planet | 479,292,741,000,000 | |
| " | 4 Satellites | 76,180,317,000 | 479,368,921,317,000 |
| Saturn | Planet | 154,351,000,000,000 | |
| " | 8 Satellites | 19,539,774,315 | |
| " | 3 Rings | 195,000,000 | 154,370,734,774,315 |
| Uranus | Planet | 25,874,664,000,000 | |
| " | 4 Satellites | 1,724,977,600 | 25,876,388,977,600 |
| Neptune | Planet | 29,107,237,000,000 | |
| " | 1 Satellite | 727,680,925 | 29,107,964,680,925 |
Total of Planets, Satellites and Rings | 691,966,535,445,840 | ||
Dividing 482,169,000,000,000,000 by 691,966,535,445,840 makes the mass of the whole of the members to be 1/696·86th part of the mass of the sun, instead of 1/700th as generally stated by astronomers.
[CHAPTER V.]
| Page | |
| [ 83] | Analysis of the Nebular Hypothesis. Separation from the nebula |
| of the rings for the separate planets, etc. | |
| [ 84] | Excessive heat attributed to the nebula erroneous and impossible |
| [ 85] | Centigrade thermometer to be used for temperatures |
| [ 86] | Temperature of the nebula not far from absolute zero |
| [ 86] | Erroneous ideas about glowing gases produced by collisions of their atoms, |
| or particles of cosmic matter in the form of vapours | |
| [ 87] | Separation of ring for Neptune. It could not have been |
| thrown off in one mass, but in a sheet of cosmic matter | |
| [ 88] | Thickness and dimensions of the ring |
| [ 89] | Uranian ring abandoned, and its dimensions |
| [ 90] | Saturnian ring abandoned, and its dimensions |
| [ 91] | Jovian ring abandoned, and its dimensions |
| [ 93] | Asteroidal ring abandoned, and its dimensions |
| [ 94] | Martian ring abandoned, and its dimensions |
| [ 95] | Earth ring abandoned, and its dimensions |
| [ 96] | Venus ring abandoned, and its dimensions |
| [ 97] | Mercurian ring abandoned, and its dimensions |
| [ 98] | Residual mass. Condensation of Solar Nebula to various |
| diameters, and relative temperatures and densities | |
| [ 100] | Unaccountable confusion in the mode of counting absolute temperature examined and explained. |
| Negative 274 degrees of heat only equal 2 degrees of absolute temperature | |
| [103] | The Centigrade thermometric scale no better than any other, and cannot be made decimal |
| [104] | The sun's account current with the Nebula drawn up and represented by Table III. |
Analysis of the Nebular Hypothesis.
We may now proceed to take the original nebula to pieces, by separating from it all the members of the solar system, in performing which operation we shall suppose the divisions between the nebula and each successive ring to have taken place at a little more or less than the half distances between the orbits of two neighbouring planets, because we have no other data to guide us in determining the proper places. These divisions have manifestly been brought about in obedience to some law, as is proved in great measure by what is called Bode's Law; although no one has as yet been able to explain the action of that law. It is no doubt certain that a division must have taken place much nearer to the outer than the inner planet in each case, if we think of what would be the limit to the sphere of attraction between the nebula and a ring just detached from it—for the attraction of the abandoned ring, and even of all those that were outside of it, would have very little influence in determining the line where gravitation and centrifugal force came to balance each other—but the data necessary for calculating what these would be are wanting. Even if they existed the calculations would become too complicated for our powers as the number of rings increased; and for our purpose it is really of very little importance where the divisions took place. The breadths of the rings would be practically the same, whether they were divided at the half distances between, or much nearer to, the outermost of two neighbouring planets; and although the extreme diameters of the consecutive residuary nebulæ would be somewhat greater, their densities and temperatures would not materially differ from those we shall find for them as we proceed in our operations. Their masses would be the same in all cases, which is the principal thing in which we are interested.
This premised, we shall first examine into the excessive heat attributed to the nebula, that being the first condition mentioned in our definition of the hypothesis.
The diameter of the sun being 867,000 miles, his volume is 341,238,000,000,000,000 cubic miles, and his density being 1·413 times that of water, his volume reduced to the density of water would be 482,169,000,000,000,000 cubic miles. Now, astronomers tell us that the whole of the planets, with their satellites and rings, do not form a mass of more than 1/700th part of the mass of the sun. If, then, we add 1/700th part to the above volume, we get a total volume, for the whole of the system, of 482,857,590,478,000,000 cubic miles at the density of water, which corresponds to a sphere of about 973,360 miles in diameter. On the other hand, the diameter of the orbit of Neptune being 5,588,000,000 miles, if we increase that diameter to 6,600,000,000 miles, so that the extreme boundary of the supposed nebula may be as far beyond his orbit, as half the distance between him and Uranus is within it, we shall still be far within the limit at which the process of separation from the nebula, of the matter out of which Neptune was made, must have begun. From these data we can form a very correct calculation of what the density—tenuity rather—of the nebula must have been. For, as the volumes of spheres are to each other as the cubes of their diameters, the cube 973,630 is easily found to be to the cube of 6,600,000,000, as 1 is to 311,754,100,720, or in other words, the density of the nebula turns out to have been 1/311,754,100,720th part of density of the whole solar system reduced to that of water.