Concrete Matter from Atomic Origins. 407 
the sum of the masses of Jupiter and all the other planets and 
satellites. On the other hand, the resultant moment of 
momentum of the motions of all parts of the Solar System, 
relatively to the fixed line of greatest moment of momentum 
through the inertial centre of* all, is chiefly due to the orbital 
motion of Jupiter and Saturn, and but in small part (about 
£q of the whole) due to the Sun's axial rotation ; as we see 
by the following table of moments of momentum, given by 
Mr. See * in his paper of 1905, " Eesearches on the physical 
constitution of the heavenly bodies/'' 
M. of ra. of orbital motion, 
that of Sans axial rotation 
being unity. 
Sun 1-0000000 
Mercury 0-00069654 
Venus 0-035444 
Earth 0-0517385 
Mars 0-00676526 
Jupiter 36-98288 
Saturn 14-98374 
Uranus 3-26959 
Neptune 4-83260 
"We have not now the simple and direct gravitational 
coalition, by motions towards the centre of a spherical 
assemblage, which we had in §§ 1 . . . 16, and which gave us 
Homer Lane's beautiful problem of a spherical gaseous 
nebula. Our vast assemblage S has moment of momentum ; 
and its main condensation has led to the formation of our 
rotating Sun. Local condensations of smaller portions of S, 
each having some share of the moment of momentum of the 
whole, have produced the planets, all revolving round the 
Sun, and rotating round their axes, in the same general 
direction ; anti-clockwise, when viewed from the northern 
side of the general plane of their orbits. 
§ 23. In Kant's and Laplace's Xebular Theory the local 
condensations, from which have been evolved the planets 
moving in their orbits round the Sun, and the satellites 
moving in their orbits round the planets, were, according to 
the suggestion presented to us by Saturn's rings, supposed 
to begin as rings of detached particles, which later became 
gravitationally drawn together into spheroidal groups, and 
formed ultimately liquid or solid approximately spherical 
bodies. This may probably be the true history of many of 
* Astr. Kachr. Bd. 169, Nov. 1905. 
