many, or some of the larger ones into multitudes, of stars.

Let us attempt to visualize the conditions which we think exist
in a newly-formed star of average mass. It should be
essentially spherical, with surface fairly sharply defined. Our
Sun has average specific gravity of 1.4, as compared with that
of water. The average density of the very young star must
certainly be vastly lower; perhaps no greater than the density
of our atmosphere at the Earth's surface; it may even be
considerably lower than this estimate. The diameter of our Sun
is 1,400,000 kilometers. The diameter of the average young star
may be ten or twenty or forty times as great. The central
volume or core of the star is undoubtedly a great deal denser
than the surface strata, on account of pressure due to the
star's own gravitational forces. The conditions in the outer
strata should bear some resemblance to those existing in the
gaseous nebula. The star may or may not have a corona closely
or remotely similar to our Sun's corona. The deep interior of
the star must be very hot, though not nearly so hot as the
interiors of older stars; but the surface strata of the young
star should be remarkably hot; for, being composed of highly
attenuated gases, any lowering of the temperature by radiation
into surrounding space will be compensated promptly through the
medium of highly-heated convection currents which can travel
more rapidly from the interior to the surface than in the case
of stars in middle or old age. Even though the star, as
observed in our most powerful telescopes, is a point of light,
without apparent diameter, its outer strata should supply some
bright lines in the spectrum, because these strata project out
beyond what we may call the core of the star and themselves act