New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1883-12-25
THE SCIENCE OF SKY-GLOWS.


weeks ago in America and Europe have en-
gagged tho serious attention of the scientific
world. While the explanation referring them
10 exceptional conditions of the atmosphere has
been generally accepted, It has not satisfied
some Of the more original inquirers In this
country and in England. Here the theory has
been advanced that the earth was passing
through a meteoric belt Of space and that the
exquisite phenomena were due 10 the presence
In the upper atmosphere of cosmical dust or
yapors detached from meteOrs by friction with
the air. In England more ingenious hypoth-
esis has been proposed. Mr.. Norman Lock
yer. the Editor OF Nature, the lead
ing English scientific periodical, discusses
In the columns of The London Times the question
whether the recent sunrises and sunsets may
not be egitimately connected with the volcanic
disturbances in Java, which occurred last
August. The idea Is not absolutely new, since
similar sky glows In South America have been
attributed 10 volcanic eruptions, but the cause
and the effect are so far removed from each
other in time and distance as to leave the
hypothesis outside the domain of ordinary con-
ceptions. Mr.. Lockyer, approaching the fact
that his conclusions will probably be secuted
esliHulOls 10 hN1AOAo VI 'AO
imagination, makes labOrious summary of
circumstandal evidence, besides availing him
self largely Of the resources Of inductiye
reasoning.
The volcanic eruptions in Java occurring on
August rs and the following day were of extra
ordinary magnitude. An island 5000 feet high
entirely disappeared; the sky was as black as
night for forty hours the quaking of the island
produced sea-wave 100 feet high volcanic
products, sand, stones and vapor were hurled
to an enormous heights and the sound OF the
eruption was heard 1000 miles away. Mr.
Lookyer finds it easy to imagine that with the
devastating forces of nature at work on this
gigantic scale millions OF tons OF matter and
millions of cubic miles OF vapor must have
been thrown into tho upper air. The coarser
elements would have Immediately descended,
but the mere dust comparable in tineness to
particles Of vapor would have remained in sus-
pension. To this volcanic dust are ascribed
the remarkable series of sky effects which have
since been produced In various quarters of the
earth. On Augustus, when the earthquake wave
reached the Seychelles and the Maurltius, there
were sunrises and sunsets unlike those wit
messed In November and December in England
and the United States, yet singular withal. On
August 81 there was an abnormal effect of sun
light In Northern Brazil In the same latitude as
tho Seychelles and on the next evening
It was observed in Venezuela. Between
the Seychelles and Brazil lies Africa,
and the volcanic dust had not been carried In
the upper air across that continent without
leaving sign. On the Gold Coast there was
remarkable sunset, and ut Trinidad (Spain)
il was repeated. This line of abnormal sunsets
is straight trajectory from east to west. There
is also O corresponding line running from south
to north, beginning with Ceylon, Madras and
Ongole, and ending with England.
While all these sky-glows and effects of color
were unusua al, there were points Of difference
between the extremes of the two lines. AT first
there was dimmng of the SUMS light; then
there was coloration Of the sun at
noon, and finally there was Il gradual
development Of ight-lengthening phenOm-
ena Mr.. Lockyer's explanation of these points
Of difference is reasonable. The volcanic dust
in the upper air must have grad
ually been thinned out. At first the coarse
grained particles were competent to absorb
light completely, and there was thick darkness
around Krakatoa; as these disappeared the sun
seemed white and dim; when the finer Particles
only were left behind, blue and red molecules
produced the Windermere effects of blue and
green and finally there was just enough float
Ing material in the atmosphere ut height Of
forty or fifty miles to reflect the SUMS
light after sunset and TO prolong tho twilight.
Mr.. Lockyer's conclusions are corroborated by
special observations. In Berlin, Professor
Helmholtz computed that the rejecting material
which caused the wonderful sunsets of Novem-
Der was at least forty miles above tho earth.
In Scotland. Profe ssor Piazzi Smyth demon
strated that the light from the blood-red sun