the
precious minutes of obscurity at Caroline Island to confirming what, in
his own persuasion, needed no confirmation--that is, the presence of
reflected Fraunhofer lines in the spectrum of the corona. Trouvelot and
Palisa, on the other hand, instituted an exhaustive, but fruitless
search for the spurious "intramercurian" planets announced by Swift and
Watson in 1878.

New information, however, was not deficient. The corona proved identical
in type with that of 1882,[550] agreeably to what was expected at an
epoch of protracted solar activity. The characteristic aigrettes were of
even greater brilliancy than in the preceding year, and the chemical
effects of the coronal light proved unusually intense. Janssen's
photographs, owing to the considerable apertures (six and eight inches)
of his object-glasses, and the long exposures permitted by the duration
of totality, were singularly perfect; they gave a greater extension to
the coronal than could be traced with the telescope,[551] and showed its
forms as absolutely fixed and of remarkable complexity.

The English pictures, taken with exposures up to sixty seconds, were
likewise of great value. They exhibited details of structure from the
limb to the tips of the streamers, which terminated definitely, and as
it seemed actually, where the impressions on the plates ceased. The
coronal spectrum was also successfully photographed, and although the
reversing layer in its entirety evaded record, a print was caught of
some of its more prominent rays just before and after totality. The use
of the prismatic camera was baffled by the anomalous scarcity of
prominences.

Using an ingenious apparatus for viewing simultaneously the spectrum
from both sides of the sun, Professor Hastings noticed at Caroline
Island alternations, with the advance of the moon, in the respective
heights above the right and left solar limbs of the coronal green line,
which were thought to imply that the corona, with its rifts and sheaves
and "tangled hanks" of rays, is, after all, merely an illusive
appearance produced by the diffraction of sunlight at the moon's
edge.[552] But the observation was assuredly misleading or
misinterpreted. Atmospheric _diffusion_ may indeed, under favouring
circumstances, be effective in deceptively enlarging solar appendages;
but always to a very limited extent.

The controversy is an old one as to the part played by our air in
producing the radiance visible round the ecl