, 1881-09-10

Yh1nx.
The scientific journals nov reaching
this coast Indicate grea. interest, among
scientific men, concerning the phenomena
Of comeis. and doubtless q rnst amount
Of material will Be presented 10 the pres
ent meeting of the American Association
for the advancement of science, at Gin
cinna;i
Ii appears that a paper has been read
by Han,mar;on before the French acade-
my, suggesting that the exhibition OF the
tail may be IN e1citation Of the ether.
Somethin. of this character, but, perhaps,
more definite vas presented by Professor
George Davidson in a communication
which he made more than month since
to Captain c. r Patterson, late superin-
tendeut of the United States Coast and
Gsodstic surrey. rs well as to two well
known astronomer at the east having
larger instruments than the Equatorial at
the Davidson observatory in this city.
Professor Davidson has aeceded to our
request for the gist Of the communication
which is A. follows:
In studying the physical phenomena of
the tail, coma and envelopes of this and
other great comets, their extraordinary
and abnormal development, the incOm-
prehensible sweep around the sun wherein
the TRANSLATION Of the matter at the ex-
tremity Of the tail must have exceeded
100, 600 miles Fer second of time comets
Of 1880 and l543). have arrived at the
following hypothesis:
That whilst there may be matter emitted
from the nucleus OF comet as necessi-
tated by the development Of the nucleus
and the formation Of the envelopes when
tho comet Is approaching the sun; and
that part OF such matter may follow in the
course Of the orbit Yet the principal
cause for the exhibition Of the tail is this
that tho light rays from the sun, in pass
ing through the matter OK the envelopes
surrour ding tho nucleus, (so intensely
heated when the Comet ia close to the sun)
become SO changed IN their ware-length
that the ETHEREAL medium itself becomes
luminous and visible in the prolonged
line Of their passage.
when the comet Of 1913 vas III peri
helion its distance from the surface Of the
sun was only one-ffth or one-sixth of the
suns radius, and must have been sub
iected to hoat sixty thousand times
greater than the earth is exposed 20.
In my judgement this hypothesis, OF
some modification of it, will account for
many and, perhaps, ali of the phenomena
referred TO, may embrace some of the
phenomena of the carona of the sun, and
even of the sodiacal light. 1t overeomes
the hitherto unsurmountable difficulty of
the sctual TRANSLATION Of matter at such
enormous vslocities
This bold proposition opens wide field
for observation and speculation. Il takes
ths phenomena from the scope of our ter.
restial comparisons, and gives it cosmi-
cal breadth. We know that there is
TRANSLATION of matter from the sun to our
eye OF from the faintest star 10 our eye,
and yet the nerve matter Of the eye is
acted upon, or, rather, the wave-kngth
of the nerve force is changed by the action
Of the other set in wave motion by the
sun and stars. We know there is no
translation of matter when cyclonic sun
storm bursts upon the suns envelope,
and yet the suspended magnetic needle is
boldly and visibly moved byth new wave
length of the other so speedily excited.
The ever changing corona of the sun
may very probably be the excitation
of the other into into new wave-lengths.
This exhibition, as well as that Of most
comets, and in part Of the zudiacal light,
arc only visible when our atmosphere Is
not iilumined by the SUMS direct rays.
The visibility of sixteen comets by day
light, during the last 1000 years, does
not in the least initiate against the by.
pothesis, On the contrary, it seems to
gain strength from it, because only great
comets very near the sun can he seen
under such circumstances.
The comet B Of 1881 exhibited Won
derful and rapid changes in its physical
appearances, and these very changes, ap-
parently, gave rise to exhibitions in the
tail verifying the hypothesis.
We understand Professor Davidson IS
preparing popular paper on ths subject
Of comets Bulletin