SCIENTIFIC SUMMARY. 
415 
new kind of matter. But the observations of Angstrom, Roscoe, and 
Clifton, and recently those of Schuster regarding the spectrum of nitrogen, 
render it probable that elementary bodies have only one spectrum : and 
since in all experimental spectra we necessarily operate only on a small 
thickness of a substance, we cannot say what new lines may be given out in 
cases where there is an immense thickness of vapour ; and hence we cannot 
conclude with certainty that because there is an unknown line in the chro- 
mosphere or corona, it implies a new substance.” 
On the photographic evidence respecting the corona, Dr. De laRue remarks, 
a If the rays and rifts were really atmospheric, it would hardly be possible 
that they should present the same appearance at different stations along the 
line of totality j indeed they would probably change their appearance every 
moment, even at the same station. If they are cislunar, the same appear- 
ances could not be recorded at distant stations. It is universally admitted 
that proof of the invariability of these markings, and especially of their 
identity as seen at widely separated stations, would amount to a demonstra- 
tion of their extraterrestrial origin. Eye-sketches cannot be depended on ; 
the drawings made by persons standing side by side differ often to an extent 
that is most perplexing. Now photographs have, undoubtedly, as yet failed 
to catch many of the faint markings and delicate details ; but their testi- 
mony, as far as it goes, is unimpeachable. In 1870, Lord Lindsay at Santa 
Maria, Professor Winlock at Jerez, Mr. Brothers at Syracuse, obtained pic- 
tures, some of which, on account partly of the unsatisfactory state of the 
weather, could not compare with Mr. Brothers’s picture obtained with an 
instrument of special construction ; * but all show one deep rift especially, 
which seemed to cut down through both the outer and inner corona clear to 
the limb of the moon. Even to the naked eye it was one of the most con- 
spicuous features of the eclipse. Many other points of detail also come out 
identical in the Spanish and Sicilian pictures. 
“None of the photographs of 1871, by Colonel Tennant and Lord Lind- 
say’s photographic assistant, Mr. Davis, shows so great an extension of the 
corona as is seen in Mr. Brothers’s photograph, taken at Syracuse in 1870 ; 
but, on the other hand, the coronal features are perfectly defined on the 
several pictures, and the number of the photographs renders the value of the 
series singularly great. . . . We have in all the views the same extensive 
corona, with persistent rifts similarly situated. Moreover, there is addi- 
tional evidence indicated by the motion of the moon across the solar atmo- 
spheric appendages, proving, in a similar manner as in 1860 in reference to 
the protuberances, the solar origin of that part of the corona.” 
The Sun’s Complex Atmosphere. — Dr. De la Rue says, u On the long dis- 
puted question of the complex atmosphere below the chromosphere, in con- 
nection with the solution of the most prominent questions connected with 
* “ Mr. Brothers had, in 1870, the happy idea to employ a so-called rapid 
rectilinear photographic lens, made by Dallmeyer, of 4 inches aperture and 
30 inches focal length, mounted equatorially, and driven by clockwork ; and 
he was followed in this matter by both Col. Tennant and Lord Lindsay in 
1871. The focal image produced, however, is far too small of an inch, 
about) ; therefore it will be desirable in future to prepare lenses of similar 
construction, but of longer focal length and corresponding aperture.” 
