14. (Page 80.) PROF. KIRCHHOFF was led to the study of a coincidence
between the bright yellow line given in an incandescent sodium vapor,
and the solar line "D," which coincidence had already been noticed by
FRAUENHOFER. Upon applying a greater dispersive power he noticed that
the line "D" was a double one; but so also was the sodium line under
these conditions. Moreover, each line of the one coincided with each
line of the other. The _suspicion_ became strong that it was the sodium
in the _sun_ which caused the "D" line. He then extended the comparisons
to other elements. He carefully measured sixty bright lines in the
spectrum of iron; and found every one of these sixty lines to
correspond with a dark in the solar spectrum.

"The overwhelming _probability_ of a common cause for both was forced
upon him, and _by calculation_ he ascertained that this probability was
as one million million million to one, in its favor."--LOCKYER.

ADDENDUM.

The great Solar Cone-space, in order to be clearly marked to the eye,
was represented in Plate I, page 30, as white. This to some readers may
be misleading; as this space when viewed transversely is not
luminous,--it is not even visible. (Pl. V.)

[Illustration: Pl. V. Solar Cone, Or Cone-Space.]

Outside of the atmospheric envelope of all spheres, there is only "_the
black of infinite space_."[E]

Retro-action between the earth and visible and invisible spheres, gives
to the earth the light which it possesses during the night-season.

FOOTNOTES:

[E] Flammarian.

Transcriber's Notes

The following typographical corrections have been made:

Page x: Heat without combustion--Inter-currents{original had
no hyphen; changed to match page 45, to which it refers}

Page 60: back and forth to maintain an{comma removed}
equilibrium.

Page 64: {quotation mark removed}The course of a balloonist

Page 102: {quotation mark added}"These clouds sometimes
range themselves

Page 107: {quotation mark added}"The overwhelming
_probability_ of a common cause

The following inconsistent hyphenation is as printed:

Page 42: just such a retro-acting inter-communication.

Page 72: might interfere with the intercommunication of light

End of the Project Gutenberg EBook of New and Original Theories of the Great
Physical Forces, by Henry Raymond Rogers

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