22S 
PROCEEDINGS OP THE PERTHSHIRE SOCIETY OF NATURAL SCIENCE. 
note all local references to birds in this work, and in so do¬ 
ing comes upon a number of references to other groups, 
which, as they are not in his department, he ignores. So 
likewise with the Reporters on Mammals, on Shells, on 
Plants, &e., each of these going over the whole work. 
Now, if instead of four or five or more persons each going 
over the Statistical Account, one person would do so and 
note the page and nature of each local reference, a great 
deal of time and labour would be saved, as each of the 
Reporters would merely have to look at the notes made to 
find out the references relating to his own subject. With¬ 
out assistance in this way from other members than the 
Reporters, a long time must elapse before we can work up 
the important subject of the bibliography. Any of our 
members who wish to assist will please communicate with 
me. 
At the general meeting, the President for the year, 
Professor James Geikie, having delivered a highly-interest- 
iug and instructive address, several papers and reports 
were submitted and discussed. 
The address and other communications will be published 
forthwith in the Scottish Naturalist. 
On September 5th, two excursions were made. One 
consisted of a dredging expedition in the Pirth of Forth; the 
other being a land excursion to Kinghorn and Burntisland. 
In the evening a meeting was held at which reports of the 
excursions were given in and specimens exhibited. 
Though the meetings alluded to above formed the regular 
routine of the Union, we must not fail to mention the 
very successful conversazione given by the Kirkcaldy 
Naturalists’ Society in honour of the Union, and to which 
the members of all the other Societies were invited. Nor 
can we conclude this Report without a grateful remem¬ 
brance of the generous hospitality so freely given to 
visitors by the members of the local Society. The whole 
arrangements of the meeting were well planned and 
successfully carried out, and though many members of the 
Kirkcaldy Society merit the thanks of the Union for their 
work in connection with the meeting, they will, we are 
sure, agree in testifying that to no one is it indebted more 
than to the Honorary Secretary, Mr W. D. Sang. 
The following paper was read :— 
“ The ‘ After-Glow,' or Extraordinary Sunsets of 1SSS-4." 
By the Rev. R. Graham, LL.D., Errol. 
That the after-glow which was observed over the greater 
part of the world during the latter part of 1883 and the 
whole of 18S4 was a really exceptional phenomenon, and 
not the result of specially serene and fine evenings, is now 
conceded by all who have directed any measure of atten¬ 
tion to the subject. The appearance of the sky im¬ 
mediately after sunset was so striking, the glory so long 
continued, and the colours so peculiar, that every one felt 
they were beholding something different from, and alto¬ 
gether beyond, an ordinary sunset. The whole western 
heavens were on serene and clear evenings literally ablaze 
with gorgeously-coloured light, in which the red, and 
yellow, and purple colours were often blended and inter¬ 
mixed in the most extraordinary and beautiful way. 
Even on those evenings when the sky was overcast the 
existence of abnormal light could be inferred from the 
longer continuance of the twilight, and from a tinge of 
greater warmth than usual in the clouded sky. Fortu¬ 
nately, we have notes of observations and descriptions of 
the phenomena by competent observers from widely- 
different localities; and from the observers in them all the 
report is the same, the appearance of the sky was excep¬ 
tional and extraordinary; whilst in many cases the gorgeous 
beauty was declared to baffle description. The glow was 
seen with equal vividness and splendour along the coast 
lines, and in the interior of the great continents. After 
continuing to be a very grand and striking phenomenon 
for nearly a couple of years, it disappeared with something 
like the same suddenness with which it had appeared in 
1883. To what then are we to ascribe it? How can we 
explain, on the known and recognised principles of science, 
an occurrence so singular and beautiful ? 
One explanation which has found much acceptance with 
men of no small scientific attainment, is, that the after¬ 
glow—as it has been called—was the result of an enormous 
amount of the finest volcanic dust suspended in the higher 
regions of the atmosphere, which, refracting and reflecting 
the sun’s rays much more than the thin air of the higher 
regions of the atmosphere usually does, occasioned the 
phenomenon. 
This theory has found much favour from the fact that, 
shortly before the glow appeared, one of the most violent 
volcanic eruptions of modern times occurred at Krakatoa 
in August, 1883. The eruption was remarkable not only 
for its violence, but also for the wide area over which it 
extended, and for the enormous amount of matter ejected 
into the atmosphere. Fortunately for science, two days 
after the greatest outburst occurred, the barque Arabella, 
with a scientific observer on board, was sailing about 1000 
miles to the leeward of Krakatoa, when a quantity of 
volcanic dust fell upon her deck. Sir Stanley analyzed 
the forms and dimensions of the particles to ascertain 
their floating and optical properties, and found them to 
