Evening star. [volume] (Washington, D.C.) 1854-1972, 1909-10-05
WHY DOES MERCURY WABBLE?
NOW THAT STAR-GAZERS KNOW
THERE Is NO VULCAN.
Victorian Discovery Proved to
Be Observation-Disclosures
Are Looking for Culprit.

For the last half century or more as
tronomers the world over have been on
the qui vive to discover a planet which
was supposed to revolve in an orbit be-
tween Mercury-the morning and evening
star-and the sun. According to Prof.
Campbell, this search may now be aban-
doned, as no such planet exists. Yet fifty
years ago it was to be found in some text
books of astronomy as a firmly estab-
lished object, just Is real as Mercury,
Venus, the earth and other planets, says
the London Globe. The conception of it's
existence came about in this wise: The
marvellous labors of Adams Cambridge
and Leverrier (Paris) established the ex-
istence of the planet Neptune from a dis
cussion of minute irregularities in the
motion of the members of our solar sys-
tenn.
Why They Thought So.
Similar labors were expended by Lever
rier In attempting to explain the yet in
applicable irregularities in the motions OF
Mercury, the innermost planet Of the sys-
tenn, and another body, yet nearer to the
sun than Mercury was supposed to exist
Confirmatory evidence was obtained from
the fact that several observers, of which
believed that they had observed such
planet, as small round disk, pass across
the face of the sun. Moreover, the physi-
clan was able to convince Leverrier that
the observation was true one. Thus was
Vulcan discovered. in 1859. only to be eff
fectively obliterated from the planetary
system fifty years later. Leverrier. who
acted as godfather to the new addition.
calculated a path and found that the
planet revolved around the sun in about
twenty days.
Yet other observers failed to see the
planet. and now Prof. Campbell an
nounces that the eclipse observations of
recent years prove almost conclusively
that the existence of such a body is a
practical impossibility Did 1t exist, it
could not possibly have eluded the care
fully designed traps set for it's detection
during the last decade. Owing to its es-
sential proximity to the sun. such a body
would be exceedingly difficult to observe
except when 1t passed in front of the sun,
appearing a black. round speck, or
when the suns light was temporarily cut
off by the interposition of the Opaque
moon, as during total solar eclipse.
Traps Set for Vulcan.
AS has been already stated, ii has not
been observed under the former condition
probably Lescarbault was mistaken or
saw sun spot-and Prof. Campbell has
used especially designed cameras during
all the recent ecIpseS, Whlch would nave
photographed 1t had it been there. His
photographs show that no planet of any
thing like sufficient size to account for
Mercury's Iapses from regularity exists.
His plates do show, however, that stars
of the ninth magnitude were photograph
ed, and he calculates that it would take
several hundred planets of this magnitude
to produce the irregularities observed.
Thus has one of the mid-Victorian dis
coveries" been quashed. but it still re-
led hat
to "wabble" Prof. Campbell suggests
that the finely divided matter which pro-
duces the zodiacal light may yet be
proved to be the culprit.