The morning news., 1894-11-11
MERCURY BEHIND A CLOUD.
The Suns Disc ObSCuTed Just Before
the Planet Passed OF.

Why 1t Gould Not Be Observed With
Satisfaction in EnRland-An English
Astronomer Comes to New York to
See It.
The transit Of Mercury passed off yester-
day almost exactly in accordance with the
standpoint, and published in yesterdays
Morning News.
Observations of the transit were made by
! Prof. Otis Ashmore of the High school by
special request of the authorities of the OBJ
servatory at Washington. Two telescopes
were arranged on the southern plaza of the
second story of the Chatham Academy be-
tween the hours Of the transit. In the
morning they were located at the eastern
end, being moved to the western end in the
afternoon. Prof. Ashmore made the OBJ
servations at one of the telescopes and Mr..
W. S. Wilson at the other Messrs. A. ].
OHara, Julian Hartridgt, f. c. Wilson
and w. S. Lawrence acted as time re-
corders during the observations.
The time used in making the calcula-
/ tiOns was that of the 18th meridian west
from Greenwich, according to which the
/ first contact of the planet was to take
/ place at 10:55:4S o'clock, and the last con-
tact at 412:3 o'clock in the afternoon. This
time is just "a minutes and q seconds
/ faster than Savannah city time.
The first contact of the planet with the
/ sun was detected just 26 seconds later than
/ the time calculated, but with telescopes of
/ moderate power this could not be avoided,
! as it is sometimes thirty or forty seconds be
/ fore the first contact can be detected A
/ few moments later both observers noted
/ what is known as the black drop As the
/ planet crosses the limb of the sun and
/ when still very near the edge it appears
| to draw out, and what is called the black
/ drop is seen between the outer
| edge of the planet and the
! outer edge of the sun. This oc-
! ours only on the internal contacts and is
! caused by what astronomers call ir-
/ radiation, or the property bright bodies
have when at a distance of looking larger
| that they are. Trere are four contacts al
/ together, two outer and two inner con
! facts, and it is these that are always
! most closely noted by the observers The
| first contact is when the edge of the planet
| appears to come in contact with the outer
| edge of the sun; the second contact is
! just after the planet has passed across
! the outer edge onto the suns disk, and
! the edges Of the two bodies still appear
/ to be in contact. The third and fourth
! contacts occur on the opposite limb Of the
sun and in the reverse order from those
| eXplair ed
The transit Of the planet was observed
with much interest for an hour or two.
and in the afternoon sometime before it
was to pass off the suns disk the obser-
| vations were begun again. To make the
| observation an entire success it was nee
essary that it be observed just at the
| time 1t was passing off the western limb
- NF.A
| was watched closely, and every minute
the time was called by the time record
| ers. At II minutes and. 3 seconds after
o'clock, 18th meridian time, it was to
pass off
/ AT o'clock there were masses of clouds
| on the western horizon and things began
| to look precarious. Mercury was accom-
| modating for a while and avoided the
clouds, but at 4:1O o'clock the clouds grew
| thicker and darker and began to cover
! up the suns face This was disappont-
| ing to be sure, but still there was hope as
two minutes and three seconds were left
according to calculations, in which to
watch for it to go off. One minute
| passed and the observers looked for reef
| between the clouds in which they might
catch just a glimpse of the departing plan
ct, but none came. Another minute passed
and a small opening in the clouds ap-
| peared near the suns disk, but Mercury
was still veiled behind them. 1t was 415
| o'clock before the suns disk came into
view, and when it did, the planet was
| gone, not to cross the disk again for the
benefit of the astronomers until Nov. 4,
| 1901 Whether il left the disk exactly on
calculated time was not determined, but
il is safe to say that ii came pretty near
it.
A transit of Mercury, as Prof. Ashmore
has explained, is impossible except when
| Mercury reaches the point in its orbit at
which the plane of it's orbit intersects the
plane of the earths orbit, thus bringing
both the planets about in the same plane.
This brings them a different intervals,
/ sometimes Of thirteen, sometimes seven
/ and sometimes three and a half years.
The next one will occur in seven years
| more, while the last one took place three
and half years ago
Observations have been made ell over
the world where the transit was visible,
and they will all be compared. There are
several matters which might be deter
mined by the observations made from
such a transit namely the distance of
the sun from the earth, the uniformity
of the earth's rotation on it's axis, whether
or not Mercury has a satellite, and other
/ astronomical problems.
Rev. Samuel Charlesworth of London.
one of the best known and most enthu-
siastic astronomers in England, came
over to New York for the purpose OF
observing the transit He is quoted in the
Herald as saying:
My object in coming to the United
States. instead of observing the tran
sit in London, is because the time for
/ observation is so much longer here than
on the other side, while the atmospheric
| conditions here are also much better"
In London, for instance the transit
view commences at 3h. sam. 40s. in the
afternoon, and ends at 4h. l6m, at which
hour the sun viii be going down, thus
adding to the difficulty of observation.
This allows twenty-one minutes for OBJ
servation, added to which viii be the dis
advantage caused by the smokiness and
mist of the atmosphere In the neighbor-
hood Of England's capital
the first contact visible I'm New York
begins at l0h. som. So. In the morning.
and does not end until 4h. Ism in the
afternoon, thus giving five hours ana
eighteen minutes for observation. Add
ed TO this is the clearer atmosphere in the
. vicinity of New York and nelghboring
places where opportunities for obsorva-
tion are possible. l expect TO observe the
. transit from Washington.
THE planet Mercury Of all the planets
Of our solar system. is, perhaps. the least