plied
by a constant factor, and added to the revolutional moment of
momentum, will remain absolutely constant.

It may be interesting to note the present disposition of this vast
inheritance among the different bodies of our system. The biggest item
of all is the moment of momentum of Jupiter, due to its revolution
around the sun; in fact, in this single investment nearly sixty per
cent. of the total moment of momentum of the solar system is found.
The next heaviest item is the moment of momentum of Saturn's
revolution, which is twenty-four per cent. Then come the similar
contributions of Uranus and Neptune, which are six and eight per cent.
respectively. Only one more item is worth mentioning, as far as
magnitude is concerned, and that is the nearly two per cent. that the
sun contains in virtue of its _rotation_. In fact, all the other
moments of momentum are comparatively insignificant in this method of
viewing the subject. Jupiter from his rotation has not the fifty
thousandth part of his revolutional moment of momentum, while the
earth's rotational share is not one ten thousandth part of that of
Jupiter, and therefore is without importance in the general aspect of
the system. The revolution of the earth contributes about one eight
hundredth part of that of Jupiter.

These facts as here stated will suffice for us to make a forecast of
the utmost the tides can effect in the future transformation of our
system. We have already explained that the general tendency of tidal
friction is to augment revolutional moment of momentum at the expense
of rotational. The total, however, of the rotational moment of
momentum of the system barely reaches two per cent. of the whole
amount; this is of course almost entirely contributed by the sun, for
all the planets together have not a thousandth part of the sun's
rotational moment. The utmost therefore that tidal evolution can
effect in the system is to distribute the two per cent. in augmenting
the revolutionary moment of momentum. It does not seem that this can
produce much appreciable derangement in the configuration of the
system. No doubt if it were all applied to one of the smaller planets
it would produce very considerable effect. Our earth, for instance,
would have to be driven out to a distance many hundreds of times
further than it is at present were the sun's disposable moment of
momentum ultimately to be transferred to the earth alone. On the other
hand, Jupiter could a