Watertown republican. [volume] (Watertown, Wis.) 1860-1906, 1877-11-07
The "Sea Bird Theory of Comets
Tails.

been the SUBJECT OF paradOXes lnnumer
able, but as yet comets have been 81
little understood, even by astronomers
that paradoxes respecting them canno
be so readily dealt with as those relatins
to well established facts. Among thor
oughly paradoxical ideas respecting
comets, however, may be mentioned
one whose author is a mathematician
Of we'll deserved repute-Prof. Tait's
/" Sea Bird Theory" of Comets Tails
According to this theory. the rapic
formation of long tails and the rapic
changes of their positions may be ex
planned on the same principle that We
explain the rapid change of appearance
of flight of sea birds when, from hay.
ing been in position where the eye
looks athwart it, the flight assumes a
position where the eye looks at it edge.
wise. In the former position it is
scarcely visible when at distance :
in the latter it is seen as we'll defined
streak ; and as a very slight change oil
position Of each bird may often suffice
to render an extensive flight thus visi.
BILE throughout its entire length, which
but few moments before had been in
visible, SO the entire length of comets
tail may be brought into view, and ap-
parently be formed in few hours
though some comparatively slight dis
placement of the individual meteorites
composing it. This paradox-for para
dox it unquestionably is-affords GU
rious illustration of the influence which
mathematical power has on the minds
of men. Every one knows that Prof.
TAFT has potential mathematical energy
competent to dispose in very short
time, Of all the difficulties involved in
his theory therefore, few seem to in
quire whether this potential energy has
ever been called into action
1t is singular, too, that other mathe-
content to take the theory on trust.
Thus, Sir w. Thompson, at the meeting
Of the British association at Edinburgh,
described the theory as disposing easily
of the difficulties presented by Newton's
comet in 1880 Glasher, in his transla-
ton of Guillemin's Les Conaetes speaks
of the theory as one not improbably
correct. though only to be established
by rigid investigation of the mathemati-
cal problems involved. In reality, not
five minutes inquiry is needed to show
any one acquainted with the history of
long-tailed comets that the theory is
quite untenable. Take Newton's comet
1t had a tail 100000 Of miles long,
extending directly from the sun as the
comet approached him, and seen, four
days later, extending to the same dis
lance, and still directly from the sun, as
the comet receded from him in an en-
tirely different direction.
According to Taits sea bird theory,
the earth was at both these epochs in
the plane of a sheet of meteorites form
ing the tail but on each occasion the
sun also was III the same plane. for the
edge of the sheet of meteorites was
seen to be directly in line with the
sun. The comets head, of course, was
in the same plane; but three points,
not IN straight line, determine a
plane. Hence we have, as the definite
theory, that the layer or stratum of
meteorites forming the tail of Newton's
comet lay in the same plane which con-
tanned the sun, the earth and the comet.
But the comet crossed the ecliptic 1.-THE
plane In which the earth travels round
the SUM- between the epochs named,
crossing it at a great angle When
crossing it, then, the great layer Of
meteorites was in the plane of the
ecliptic; before crossing it the layer
was greatly inclined to that plane one
way, and after crossing it the layer.was
greatly inclined to that plane another
way. So that we have in no way es-
capped the difficulty which the sea bird
theory was intended to remove. If it
was a startling and, indeed, incredible
thing that the particles along a comets
tail should have got round in four days
from the first to the second position of
the tail considered above, it is startling
and incredible that mighty LAYER of
meteorites should have shifted bodily
in the way required by the sea bird
theory. Nay, there is an element in
our result still more startling than any
of the difficulties yet mentioned, and
that is the singular. care which the great
layer Of meteorites would seem to have
shown to keep its plane always passing
through the earth, with which it was in
no way connected. Why should this
preference have been shown by the
meteor flock for our earth above all
other members Of the solar system p
seeing that the sea bird theory requires
that the comet, and not Newton's comet
alone, but all others having tails, should
not only be complaisant with respect to
our little earth, but should behave in a
totally different way with respect to
every other member of the suns fam
lily. We can understand that, while
several have been found who have APP
plauded the sea bird paradox for what
it might do in explaining comets tails,
its advocates have as yet not done much
to reconcile it with cometic observa-
ton. -Richard A. Proctor, Belwavia.
A Railway Hen.
The Shelbyville Gazette is responsible
for this, the latest hen story: A hen
made q nest in a box in a. baggage car.
and in the course of time had fifteen
eggs, and stuck to them through thick
and thin, night and day. except to step
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