Nov. 4, 1869 | 
NATURE 
) 
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 dzzarre and 
puzzling to the last degree! The most definite statement 
on the subject is, that it is nothing more nor less than a 
permanent 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 lines) 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 settled, were the new hypothesis 
less startling than it is. The position of the line is 
approximately shown in the woodcut (Fig. 1) near E, 
together 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 
Harkness 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 
equally 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 of polarised—a conclusion, as 
M. Faye 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 
carefully studying eelipses ; 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 finish which may be gathered 
from the accompanying reproduction of one of them. 
Fic. 2.—Copy of a photograph of the Eclipse of August 7, obtained by 
Professor Morton’s 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 Sz//zman’s 
Fournal, “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 American 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. NORMAN 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 Astronomische Nachrich- 
zen, 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 
Antiguités préhistoriques di Danemarck. By M. Madsen. 
Folio, pp. 19, with 45 engraved plates, some coloured. 
Price 36s. (London: Williams and Norgate.) 
Ips 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 
admirably executed, those of the great chamberedtumulus at 
Uby being particularly successful. Plates xv. to xx. give 
