ABSTRACT

A new work on spherical astronomy by Professor Newcomb is typical of this form of economy of labour, and is a notable contribution to the subject. Dynamical astronomy, as we have seen, is a much more recent product, and may be said to have owed its birth to Newton, and its vigorous development to the great continental mathematicians and physicists to whom reference has already been made. Newtonian theory has hit herto failed to account, or to modify the law of gravitation itself in order to compromise with those discordances. Very valuable work has also been done, and is still being attempted, on the theoretical 'figure' of celestial bodies. The new cosmogony regards Saturn's ring as the necessary ultimate form of a satellite revolving too near its primary to retain stability under the enormous tidal action, and hence breaking up into particles scattered round its original orbit.