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Nature
(Thursday, November 4, 1869)

Lubbock, John
Madsen's Danish antiquities,   pp. 15-16


Page 15


iMsz. 4, i t69]
NA TURE
should get a sort of key to the strange cypher band called
the spectrum, which might prove of inestimable value,
not only in the future, but in a proper understanding of
all the telescopic observations of the past. We should, in
fact, be thus able to translate the language of the spectro-
scope. Again, by observing the spectrum of the same
prominence both before and during, or during and after
the eclipse, the effect of the glare on the visibility of the
lines could be determined-but I confess I should not like
to be the observer charged with such a task.
  What, then, is the evidence furnished by the American
observers on the nature of the corona? It is bizarre and
puzzling to the last degree ! The most definite statement
on the subject is, that it is nothing more nor less than a
fermanent solar aurora! the announcement being founded
on the fact, that three bright lines remained visible after
the image of a prominence had been moved away from the
slit, and that one (if not all) of these lines is coincident with
a line (or jibes) noticed in the spectrum of the aurora
borealis by Professor Winloch.
  Now it so happens that among the lines which I have
observed up to the present time-some forty in number-
this line is among those which I have most frequently
recorded: it is, in fact, the first iron line which makes its
appearance in the part of the spectrum I generally study
when the iron vapour is thrown into the chromosphere.
Hence I think that I should always see it if the corona
were a permanent solar aurora, and gave out this as its
brightest line ; and on this ground alone I should hesitate
to regard the question as setiled, were the new hypothesis
less startling than it is.  The position of the line is
approximately shown in the woodcut (Fig. i) near E,
tZgether with the other lines more frequently seen.
  It is only fair, however, to Professor Young, to whom is
due this important observation, to add that Professor
lIlarkness also declares for one bright line in the spectrum
of the corona, but at the same time he, Professor Pickering,
and indeed others, state its spectrum to be also continu-
ous, a remark hard to understand unless we suppose the
slit to have been wide, and the light faint, in either of which
cases final conclusions can hardly be drawn either way.
  So much, then, for the spectroscopic evidence with which
we are at present acquainted on the most important point.
The results of the other attacks on the same point are
equialy curious and perplexing. Formerly, a favourite argu-
ment has been that because the light of* the corona is
polarised; therefore it is solar. The American observers
state that the light is not polariseI-a conclusion, as
M. taye has well put it, " very embarrassing for Science."
Further,-stranger still if possible,-it is stated that another
line of inquiry goes to show that, after all, Halley may be
right, and that the corona may really be due to a lunar
atmosphere.
  I think I have said enough to show that the question
of the corona is by no means settled, and that the new
method has, by no means superseded the necessity of
carefdully studying eclipses; in fact, their observation has
become of much greater importance than before; and I
earnestly hope that all. future eclipses in the civilised area
in the old world will be observed with as great earnest-
ness as the last one was in the new. Certainly, never
before was an eclipsed sun so thoroughly tortured with all
the instruments of Science. Several hundred photographs
were taken,with a perfection of finishwhichmaybe gathered
from the accompanying reproduction of one of them.
  FIG. 2.-Copy of a photograph of the Eclipse of August 7, obtained by
                  Professor Morton', party
  The Government, the Railway and other companies,
and private persons threw themselves into the work with
marvellous earnestness and skill; and the result was that
the line of totality was almost one continuous observatory,
from the Pacific to the Atlantic. We read in Si/liman's
7ournal, " There seems to have been scarcely a town of any
considerable magnitude along the entire line, which was
not garrisoned by observers, having some special astro-
nomical problem in view." This was as it should have
been, and the Amtuerican Government and men of science
must be congratulated on the noble example they have
shown to us, and the food for future thought and work
they have accumulated.
                              J. NORMIAN LOCKYER
  Since writing the above, I find the following inde-
pendent testimony in favour of Dr. Frankland's and my
own notion of the corona in the Astrononische Nachrich-
ten, from the pen of Dr. Gould. He says:-" Its form
varied continually, and I obtained drawings for three
epochs at intervals of one minute. It was very irregular
in form, and in no apparent relation with the protuberances
on the sun, or the position of the moon. Indeed, there
were many phenomena which would almost lead to the
belief that it was an atmospheric rather than a cosmical
phenomenon. One of the beams was at least 30' long."
     MADSEN'S DANISH ANTIQUITIES
Antiguitislprihistoriques du Danernarck. By M. Madsen.
    Folio, pp. 19, with 45 engraved plates, some coloured.
    Price 36s. (London: Williams and Norgate.)
THIS work contains forty-five carefully executed plates
     of Danish Antiquities belonging to the Stone age.
The first represents the Shellmound of Fannerup; a diffi-
cult subject, very faithfully rendered, as the present writer
can testify. The three following plates give the common
and characteristic objects of the Shellmounds. Then follow
ten plates devoted to tumuli and dolmens. These are
admirablyexecuted, those of the great chamberedtumulusat
Uby being particularly successful. Plates xv. to xx. give
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