--Immanuel Kant's conception of the formation of the
world--Defects in Kant's conception--Laplace's final solution of
the problem--His explanation in detail--Change in the mental
attitude of the world since Bruno--Asteroids and
satellites--Discoveries of Olbers1--The mathematical calculations
of Adams and Leverrier--The discovery of the inner ring of
Saturn--Clerk Maxwell's paper on the stability of Saturn's
rings--Helmholtz's conception of the action of tidal
friction--Professor G.  H.  Darwin's estimate of the consequences
of tidal action--Comets and meteors--Bredichin's cometary
theory--The final solution of the structure of comets--Newcomb's
estimate of the amount of cometary dust swept up daily by
the earth--The fixed stars--John Herschel's studies
of double stars--Fraunhofer's perfection of the refracting
telescope--Bessel's measurement of the parallax of a
star,--Henderson's measurements--Kirchhoff and Bunsen's
perfection of the spectroscope--Wonderful revelations
of the spectroscope--Lord Kelvin's estimate of the time that
will be required for the earth to become completely cooled--
Alvan Clark's discovery of the companion star of Sirius--