The Helena independent. [volume] (Helena, Mont.) 1875-1943, 1894-11-10
Mercury viii To-day Make Her
Thirteenth Transit During tho
Present Century.
An Astronomical Event OF Much
Interest From a Scientific
Standpoint
IRvIsibIs To the Naked Eye, bat Msy Bs
Viewed with Field Olaases-A
Tiny speok.

Washington, Nov. 0,-The transit OF
Mercury viii be observed by some dis
tlnguished persons ut the naval observ-
at0ry here tomorrow at 1Aj n. m. and
iI2 D. m. Secretary Herbert has in
vited president and MRS. Cleveland
ana all members OF the cabinet. with
their ladies' and families. % visit the
observatory 20 view the phenomena
through the great telescope.
For the thirteenth and last time dur
Ing this century the planet Mercury
VIII cross the SUMS disc, causing the
phenomenon known as a transit"
Unfortunately, the planet being SO
small, II can only be seen by means OF "a
telescope or pair of field glasses. Then
exactly at 1862 a. m, mean Denver
local time, the eastern or rather north
eastern edge OF the sun will appear as
though notched by small. Intensely
black spot. Gradually the notch will
Increase until the whole OF the planet
appears upon the bright disc. Il will
then travel across until about two
O'Clock, when the western edge OF the
sun will appear 10 be notched. AT 2:I5.5
.. m. the planet will disappear from
human gaze and will not again be WIS.,
ible except 10 the most powerful tele-
scopes for several days,owing to it's
proximity 10 the intense light OF the
sun.
Its first appearance 10 human obser-
walton will be about Nov. 20. when it
VIII appear as "A morning star imme-
diately preceding the rising orb OF day.
IL Will first appear as a narrow, slender
crescent OF sllvery. twinkling white
light, and, as II travels away from the
sun, VIII gradually take the shape of
a perfect hemisphere. Then the planet
VIII rise considerably I'm advance OF the
sun. Gradually as the distance in
creases. Mercury Will take the form OF
a perfect sphere. and then, again draw
ing nearer TO Sol, on the other side ot
the orbit Will successfully repeat the
former changes but in reverse order.
peculiar feature connected with a
transit OF Mercury is the regularity OF
It's appearance at certain times of the
year. The phenomena invariably occur
within two or three days of May z or
Nov. ., the regularity being caused by
the orbit OF the small planet being 80
inclined that IL can get between the
| ~ niAh Ntll dDDul Iuttt O0teN.
The transit VIII be closely watched
by all astronomers on this side OF the
earth. The principal value OF the OBJ
servntions lie mainly in the fact that
such an occurrence furnishes means
| or determining more accurately the ex-
act form of the planets orbit and also
The facility afforded by n sharply de-
fined black disc against bright back
ground for correctly measuring It's size.
/ q No. Yfs.Rau
can also be made. An atmosphere sim
liar to that surrounding the earth or
Venus will form a sort OF halo around
a planet as IL passes across the sun.
| This is caused by the refraction of
light varying directly in proportion TO
the atmospheric envelope surrounding
the planet. Even I'm the most powerful
telescopes no such ring or halo Is 20
be seen and II is more than likely that
Mercury Is cold, barren, airless globe
similar TO our moon.
Mercury Is the densest OF the plane
tary neighbors of the Iearth, being
slightly more than one-ffth heavier.
Correctly speaking. taking the earth's
density at one. Mercury's density Ia
l,23i The apparent diameter of the
planet osclllates between "a seconds
and IL seconds, but its real diameter Is
3,OS2 miles, or somewhat more than
/ lhAlf-AHllh Alf Size ol Nflf tAIln. the
mean distance between the two planets
being 29 100000 miles IL Is the nearest
planet 20 the sun, being approximately
| one-third the enrth's distance.
To the superstitious a transit OF Mer-
curry always suggests dark deeds I'm it's
alleged influence over mankind. Some,
however. attribute To the planets
phases an influence OF commerce and
gain. The derivation OF these supersti-
tions probably lies In the ancient myth
lological lore Mercurius was the Ro-
man divinity OF commerce and mercan-
tile gain. He was the god OF orators,
disclaimers and merchants. but was also
the divinity OF thieves, pick-pockets
and all dishonest persons. In mythol-
ogy IL is said that on the day Of his
birth he gave proof OF his craftiness by
stealing away the oxen OF Admetus,
which Apollo tended. lie gave other
tokens OF his thievish tendency by taxi
ing the quiver and arrows OF Apollo.
Ills fame tn this respect was somewhat
increased when he robbed Neptune OF
| his trident, Venus OF her girdlc. Mars
of his sword. Jupiter ot his sceptcr and
Vulcan OF many of his mechanical in
struments As sometimes occurs. even
I in thrsc days, whom the young rascal
proved his worthlessncs0 he was taken
| IN hand by Jupiter, the god OF lightning
later tue tClekiHpn-unu made hlH
messenger. Therefore II In these days
the public has any fault 10 Ind with the
actions 0f the lattef-day disciples OF the
ancient god, some allowance should be
made for the planetary influence,
| In looking nt the transit during the
day through field glasses or telescopes.
| it is uf the utmost importance that
piece OF well smoked glass be placed be-
tween the eye and oycpiece OF the tcle-
scope or field glasses. A minute exam
Iination should be made 10 see that the
hlm uf SCOT IL not scratched before the
eve IL directed toward the sun. IL
should be remembered that should the
rays OF the sun be focused ON the eye
without being filtered down through
very dark or smoked glass. blindness
would probably bo the result
! Amateur photographers viii also
have an opportunity for an unusual exc
Ipcrimcnt. With a lens OF considerable
focal length and n good quick shutter
n negative may De made from which It
Twill be possible 60 enlarge and get n
very fair picture OF the small black
Iplanet ON the SUMS dlsc, The ordinary
Ibnnd camera or kodack is worthless for
the experiment, A tripod camera using
IA lens, single combination preferable,
Inf l6 Inches or more focus, viii De found
serVlceable. The camera should De To-
lcused on some distant object ana
small stop" inserted In the lens tube,
The shutter should bee set at itn ilghteat
Itonsion and all viii be rcndy. The
mates. 10 avoid excessive hhlnuon,
must be coated on the back win 'no.'
lhnlntion" compond. In the absence OF
4 a. IA Nf4fI.