, 1875-03-17
THE TOTAL
ECLIPSE OF THE SUN.
{From the Herald.)

from the transit of Venus expeditions been
garnered when the restless spirit of astro-
nomic inquiry is to be diverted toward the
approaching eclipse of the sun. This
eclipse will be total, and will occur on the
6th of next April, when, according to the
English astronomer Hind, there will be
the best opportunity for the observation
of totality likely to be offered till toward
the close of the century. Although the
course of the central line in this eclipse is
principally a sea track fine opportunities
for observing it will be had during it's pas
sage from the Nicobar Islands, in the Bay
of Bengal, to Siam. The central eclipse,
it is computed, passing from the Nicobars
crosses Bentinck Island, where the maxi
mum period Of totality will be four min
utes and seventeen seconds. At several
other adjacent insular stations the phe-
nomenon will be observable for about the
same space of time. The king of Siam
has heartily invited British and other as
tronomers to make the observations with
in his dominions and volunteered to ex-
tend them every facility and hospitali-
ty.
Although, in an astronomical point of
view, the observation of a total eclipse is
OF far less Importance than that of the re-
cent great transit, the former is only secon.
Diary to the latter in general scientific in
terest. The study OF the constitution Of
the sun and its coronal atmosphere, which
the spectroscopic examination of a total
eclipse affords, is held by the ablest scien,
lists of the day as Of transcendent impor-
lance and as likely to furnish the solution
of many practical and utilitarian problems.
The climatic changes that occur on the
earth and their bearing on O vast array of
problems connected with navigation, agri-
culture and health, send the investigator
to seek in the sun for the causes of these
changes. These changes are not i%rration-
ally traced to solar action, if we regard the
marvellous revelations of the spectroscope
as to the chemical nature of the suns at
mosphere. The corona, when seen in a
clear sky, is manifestly a purely solar phe-
nomenon, produced by an immense body of
gas-probably incandescent yapor of iron
supposed to be erupted from its glowing
surface as fire from the crater Of a terrestri-
al NOICduO' uO ISSUE Vi ulOISG SLCdtl
from q boiler under ordinary pressure is
known to generate large quantities of cleo
tricity. But how inconceiyably vast must
be the torrents generated by the hydrogen
outbursts from the countless solar c~raters,
supposed to beIch forth their flames with
q velocity Of a hundred and twenty miles
an hour! The researches connected with
the several eclipses since 1860 have demon
strated, by almost complete spectra, that
hydrogen and the iron metals, with pro-
badly those of the alkaline earths, exist in
the sun. That further startling and in
structive spectroscopic revelations are in
reserve for the eclipse observer is not to
be doubted. The application of spectrum
photography renders this more certain.
And all these modern devices, with others
we cannot stop to mention, will be brought
into requisition if the invitation of the
King of Siam is accepted by the English
astronomers.
1t is said that the Royal Society will en-
e~rgetically move in the matter and make
preparations for an occupation of the field
OF observations. We presume it is too
late for sending out any cooperative party
from this country.