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POPULAR SCIENCE REVIEW. 
Baikul to the Ootacamund series ; and taking into consideration the distance 
between the two stations, it is evident that the structure must be either 
due to some dark body in the corona, or to some semi-transparent body 
situated between us and the corona, at a great distance from the earth. 
“ The form of structure is similar to that which has often been observed in 
the nuclei and the concentric comse of comets ; and it seems not very un- 
reasonable to suppose that this may really be a photograph of a faint though 
large comet near to perihelion. 
u An undoubted comet has been seen projected on the brilliant background 
of the photoshere (I refer to Pastorff’s observations of the comet of 1819*) ; 
and much fainter comets would be visible when projected on the compara- 
tively feeble light of the corona. It seems, therefore, not very improbable 
that both this structure and the parabolic arc observed by Dr. Winnecke 
may have been due to comets which happened to be situated between us 
and the corona during times of total eclipse. And it is not impossible that 
such giant comets may exist in great numbers in the immediate neighbour- 
hood of the sun, though by reason of their faintness, or the short time of 
their ebullition, they are not visible to us either before or after their peri- 
helion passage.” 
Total Eclipse of April 16, 1874. — This eclipse did not attract anything 
like the attention which was directed to the eclipses of 1868, 1869, and 
1870 — a circumstance showing that the discussion of disputed points may 
serve a useful scientific purpose; for it can hardly be doubted that the 
difference resulted from the fact that when the former eclipses were about to 
occur matters were under discussion of which the observations made during 
these eclipses disposed, whereas in the present year no such discussion had 
been aroused. Nevertheless, the observations made by Mr. Stone, the 
Astronomer Royal at the Cape, are full of interest: — “I observed the 
eclipse,” he says, il from Klipfontein, a station about 3,000 feet above the 
sea level. The sky was perfectly clear, and no finer day could have been 
wished for. I had borrowed a four-inch telescope, mounted as an altazimuth, 
from Mr. H. Solomon. My spectroscope was one with two dense flint 
prisms of 60° ; a fair amount of dispersion, therefore, being thus obtained. 
My great difficulty was to attach the spectroscope firmly to the telescope. 
Ultimately I was obliged to give up all idea of using the prism of com- 
parison, and fix the tubes together by wrappers of wash-leather. In this way 
I secured a very firm connexion between the spectroscope and telescope. I 
placed two wires in the focus of the telescope of the spectroscope for esti- 
mations, and determined to measure only the position of one line in the 
corona, the micrometer wire being left untouched until the reappearance 
of the Fraunhofer lines, when the differences between the line measured 
and these lines could easily be fixed. 
u The slit was set as wide as would allow of a clear and distinct view of 
the Fraunhofer lines. This I did because I expected to find the spectrum of 
* As well as to the nebulous spot observed by him upon the sun in May 
1828. See the “ Monthly Notices,” November 1873. It may be added that 
the comet can hardly have been a tailed one, as the envelopes are on the 
side farthest from the sun. 
