The Seattle post-intelligencer. [volume] (Seattle, Wash. Terr. [Wash.]) 1888-1914, 1892-12-11

convenient phase for measurement. AS It
| is. however, Prof Barnard must have his
observations supplemented by those at
some other observatory in q considerably
different longitude. Here is the difficulty.
Telescopes OF sufficient power to show the
new object there may be. but the excep-
tionaily favorable conditions for o5serva-
ton presented on the top of Mount HAM
Hton are not easily to be. paraiieseo else.
where 1t is. however, generally found
that once an object has been discovered 1t
IS frequently possible to observe 1t again
with telescopic advantages greatly inferior
to those by which the discovery was mace.
As to the physical character of the new
satellite it seems difficult 10 offer any sur
mise. 1t seems probable that so small an
object must be in the solid state. We are
in the habit of accounting for the OBJ
viously non-solid condition of Jupiter
himself by the excessive heat which ne
still contains. But the new satellite bears
to Jupiter proportion, Get us say, OF
grain of mustard seed to q cocoanut. IL
therefore appears that though such vast
bulk as Jupiter may not yea have had time
to cool down into the solid form, the same
can hardly be averred of its tiny com
panion. II there should be any fluid
materials on the small satellite they must
be distracted by the most terrific tides. 1t
is certain that seas on its surface would be
submitted to tidal forces at least thirty
times as potent as those on the earth.
There cannot be doubs that the new
satellite will afford much occupation for
mathematicians. 1t is hardly possible
that 1t will not be the meaes Of leading
fresh impetus to the study OF the entire
Jovian system. At the same time We
must remember that the detection Of the
new body does not offer to as, so far as We
are at present advised, any interesting in
formation of the same character as that
which the satellite of Mars presented. The
mass of Mars was an element not very
confidently known until the satellites had
been discovered, and their distances and
periods measured. The mass of Jupiter
however, is one of the most carefully de-
termined elements of the sear system. 1t
has been accurately asceTtained by the
movements of its satellites. especially
of the fourth. There can hardly be a
doubt that the value assigned to
it is right to within one-thousandeth part
of the whole. We have, therefore, nothing
further of this kind to expect from the
new satellite. It will also be remembered
that one of the most astonishing features
of the Marian system of moons was the
extraordinary rapid motion of the inner
of the two. by which it coursed three
times round the planet before the planet
turned round once. This fact at the time
Of its announcement was unique In the
whole solar system. There was never a
case known before in which a secondary
time than the primary accomplished ro-
tation. And 80 far as this discovery
in regard to Jupiter goes, the pc
culiar feature of the inner moon
of Mars still remains unique. Even
though the period of the satellite is only
about twelve hours, it is sill about two
hours longer than the time which Jupiter
requires to spin round bis axis. We
ought, however, here to notice that the
rotation of Jupiter is exceptionally rapid.
If the great planet required as much time
for one of his rotations as does Mars or
the earth, then the new satellite of Jupi-
ter would present. the same analogous
feature to its primary as We actually find
in Mars in its inner satellite.
There are so many mysteries about
Jupiter THAT We are specially glad to
welcome the new satellite in the hope that
somehow it will afford clue to their ex-
PLANTATION. We are still ignorant of the
true nature Of the great red spot which
has a period of rotation different from
that of the planet itself. Then there are
the small black spots which appear to re-
volve round the planet in few minutes
less time than the planet itself requires.
Nor is it likely that Prof. Barnard's DIS
covery will remain an isoiated one. The
announcement speaks, it is true, Of only
one new satellite. but in sill probability
this is one of those discoveries which is
often succeeded by others Of the same
class. In the meantime VIZ can only re-
mark that the achievement has given q re-
suscitated interest to good old-fashioned
telescope work. This is the more needed
because in these modern days of photo
graphic and spectroscoptc astronomy
there is some tendency to regard the more
simple form of observation as an art of the
past. SIR ROBERT BALL,
Astronomer Royal for Ireland.
Ladies, go to ]. J. Wittwer, el3 Front street
and have yOur hair prOparly ate,nded IN