[Footnote 25: If the "rice-grain" appearance is thus produced by the
tops of the ascending currents (and M. Faye accepts this
interpretation), then I think it excludes M. Faye's hypothesis that the
Sun is gaseous throughout. The comparative smallness of the light-giving
spots and their comparative uniformity of size, show us that they have
ascended through a stratum of but moderate depth (say 10,000 miles), and
that this stratum has a _definite_ lower limit. This favours the
hypothesis of a molten shell.]
[Footnote 26: I should add that while M. Faye ascribes solar spots to
clouds formed within cyclones, we differ concerning the nature of the
cloud. I have argued that it is formed by rarefaction, and consequent
refrigeration, of the metallic gases constituting the stratum in which
the cyclone exists. He argues that it is formed within the mass of
cooled hydrogen drawn from the chromosphere into the vortex of the
cyclone. Speaking of the cyclones he says:--"Dans leur embouchure evasee
ils entraineront l'hydrogene froid de la chromosphere, produisant
partout sur leur trajet vertical un abaissement notable de temperature
et une obscurite relative, due a l'opacite de l'hydrogene froid
englouti." (_Revue Scientifique_, 24 March 1883.) Considering the
intense cold required to reduce hydrogen to the "critical point," it is
a strong supposition that the motion given to it by fluid friction on
entering the vortex of the cyclone, can produce a rotation, rarefaction,
and cooling, great enough to produce precipitation in a region so
intensely heated.]