1884.] Recent Literature, 1023 
difficulties that others have magnified. At pages 111-113, reasons 
are given why, in a contracting, rotary spheroid, “an annular 
mass of relatively considerable amount would separate, and a 
secular interval would intervene before the separation of another 
annular mass.” This ring would be completed when the cen- 
trifugal force at the equator exceeded the centrifugal force plus 
the attractions of the separated ring. At page 121-3 the causes 
of the rotation of the mass derived from a ring, and those 
which influence its direction, are treated of. In treating of the 
general cosmogonic conditions of a cooling planet Professor 
Winchell appears to coincide with the theory which would make 
the center of the earth solid; he gives reasons why “ sub-meri- 
dional trends” should be early established upon a cooling globe, 
so that all the primitive wrinklings of the crust should extend 
across its parallels; explains the craters of the moon by the tidal 
outflow of molten matter; and gives reasons for believing that 
planetary tides cause the development of much heat. The floor 
of the primitive ocean had, says our authority, an igneous origin, 
but it no longer exists on this earth, having been destroyed by 
sedimentation from above, and by fusion from below. Professor 
Winchell supports the older theory of a shrinking globe and a 
wrinkling crust, against the objections of LeConte, Dutton, Fisher, 
and others, 
divergent from that of the earth, and probably an atmosphere 
admitting light aud heat to about an equal extent with that of the 
tarth; and Jupiter to be still lingering in the high thermal stages 
of planetary life. The next chapter treats of planetary decay, of 
€ final disappearance of the continents beneath the ocean by the 
Operation of erosion and the cessation of elevatory forces, and 
of ultimate planetary death from refrigeration and other causes. 
E the third part the systems outside of our own are dealt with. 
Tuptive action on an incrusted globe is spoken of as the most 
Probable cause of variable and temporary stars. In the last part 
the Speculations of the great philosophers, of Kepler, Descartes, 
itz, Swedenborg, Wright, Kant, Sir W. Herschel, Laplace, 
are brought together and compared. It is shown that eet 
ofa - 
Newton and the great mathematicians of the eighteenth century, 
While the etailed theory of world-formation is principally due to 
