A paper was read on March 2, 1882, by Dr. C. W. Siemens at the Royal
Society, and he published an article on “A New Theory of the Sun” in
the April number of the _Nineteenth Century_. All who have read my
essay on “The Fuel of the Sun” are surprised at the statement with
which the magazine article opens, viz.: that this “may be termed a
first attempt to open for the sun a debtor and creditor account,
inasmuch as he has hitherto been regarded only as a great almoner
pouring forth incessantly his boundless wealth of heat, without
receiving any of it back.”
Some of my friends suppose that Dr. Siemens has wilfully ignored the
most important element of my theory, and have suggested indignation
and protest on my part. I am quite satisfied, however, that they are
mistaken. I see plainly enough that although Dr. Siemens quotes my
book, he had not read it when he did so; that in stating that “Grove,
Humboldt, Zoellner, and Mattieu Williams have boldly asserted the
existence of a space filled with matter,” he derived this information
from the paper of Dr. Sterry Hunt which he afterward quotes. This
inference has been confirmed by subsequent correspondence with Dr.
Siemens, who tells me that he saw the book some years since but _had
not read it_. My contributions to the philosophy of solar physics would
have been far more widely known and better appreciated had I followed
the usual course of announcing firstly “a working hypothesis,” to
warn others off the ground, then reading a preliminary paper, then
another and another, and so on during ten or a dozen years, instead of
publishing all at once an octavo volume of 240 pages, which has proved
too formidable even to many of those who are specially interested in
the subject.
I am compelled to infer that this is the reason why so many of the
speculations, which were physical heresies when expounded therein,
have since become so generally adopted, without corresponding
acknowledgment. This is not the place for specifying the particulars of
such adoptions, but I may mention that in due time “An Appendix to the
Fuel of the Sun,” including the whole history of the subject, will be
published. The materials are all in hand, and only await arrangement.
In the meantime I will briefly state some of the points of agreement
and difference between Dr. Siemens and myself.
In the first place, we both take as our fundamental basis of
speculation the idea of an universal extension of atmospheric
matter, and we both regard this as the recipient of the diffused
solar radiations, which are afterwards recovered and recondensed, or
concentrated. Thus our “fuel of the sun” is primarily the same, but, as
will presently be seen, our machinery for feeding the solar furnace is
essentially different.
Certain desiccated pedants have sneered at my title, “The Fuel of the
Sun,” as “sensational,” and have refused to read the book on this
account; but Dr. Sterry Hunt has provided me with ample revenge.
He has disentombed an interesting paper by Sir Isaac Newton, dated
1675, in which the same sensationalism is perpetrated with very small
modification, Sir Isaac Newton’s title being “Solary Fuel.” Besides
this, his speculations are curiously similar to my own, his fundamental
idea being evidently the same, but the chemistry of his time was too
vague and obscure to render its development possible. This paper was
neglected and set aside, was not printed in the Transactions of the
Royal Society, and remained generally unknown till a few months ago,
when the energetic American philosopher brought it forth, and discussed
its remarkable anticipations.
Dr. Siemens supposes that the rotation of the sun effects a sort of
“fan action,” by throwing off heated atmospheric matter from his
equatorial regions, which atmospheric matter is afterwards reclaimed
and passed over to the polar regions of the sun. This interchange he
describes as effected by the differences of pressure on the fluid
envelope of the sun; the portion over the polar regions being held
down by the whole force of solar gravitation, while the equatorial
atmosphere is subject to this pressure, or attraction, minus the
centrifugal impulse due to solar rotation. He maintains that this
“centrifugal action, however small in amount as compared with the
enormous attraction of the sun, would destroy the balance, and
determine a motion towards the sun as regards the mass opposite the
polar surface, and into space as regards the equatorial mass.” He
adds that “the equatorial current so produced, owing to its mighty
proportions, would flow outwards into space, to a practically unlimited
distance.”
I will not here discuss the dynamics of this hypothesis; whether the
reclaiming action of the superior polar attraction would occur at the
vast distances from the sun supposed by Dr. Siemens, or much nearer
home, and produce an effect like the recurving of the flame of his
own regenerative gas-burner; or, whether he is right in comparing the
centrifugal force at the solar equator with that of the earth, by
simply measuring the relative velocity of translation irrespective of
angular velocity. I will merely suggest that in discussing these, it
is necessary, in order to do justice to Dr. Siemens, to always keep in
mind the assumed condition of an universal and continuous atmospheric
medium, and not to reason, as some have done already, upon the basis
of a limited solar atmosphere with a definite boundary, from beyond
which particles of atmospheric matter are to be flung away into vacuous
space, without the intervention of all-pervading fluid pressure.
It is evident that _if_ such fan action can bring back _all_ the
material that has received the solar radiations, and which holds them
either as temperature or otherwise, the restoration and perpetuation of
solar energy will be complete, for even the heat received by our earth
and its brother and sister planets would still remain in the family,
as they would radiate it into the interplanetary atmospheric matter
supposed to be reclaimed by the sun.
But, as Mr. Proctor has clearly shown, the rays of the sun cannot do
all the work thus required for his own restoration without becoming
extinguished as regards the outside universe; and if the other
suns—_i.e._, the stars—do the same they could not be visible to us.
Thus Dr. Siemens’ theory removes our sun from his place among the
stars, and renders the great problem of stellar radiation more
inscrutable than ever by thus putting the evidence of our great
luminary altogether out of court.
My theory, on the contrary, demands only a gradual absorption of solar
and stellar rays, such as actual observation of their varying splendor
indicates.
If space were absolutely transparent, and its infinite depths peopled
throughout, the firmament would present to our view one continuous
blazing dome, as all the spaces between the nearer stars would be
filled by the infinity of radiations from the more distant.