The times dispatch. [volume] (Richmond, Va.) 1903-1914, 1910-05-15

telescope drag would make a blur upon
the attached cameras.
/ There are two OF these cameras, and
with their tubes arranged side by side
they look like a pair of giant opera
glasses. bolted to the telescopes barrel
and turning with It. They have tubes
instead OF bellows because all distant
heavenly bodies have the same focus
For the same reason there is no
ground glass
IT, with his eye at the eyepiece OF
the telescope, Mr. Peters sees to 1t
that the telescope is aimed straight. he
| knows that the twin cameras are TO-
cused upon the same point
The lenses OF the cameras are six
inches In diameter and each focuses
| the comet back through a tube a little
over n yard In length and having
square clamp at the rear. Into these
clamps he puts his pair OF plate hold
ers. each containing only ono plate,
and therefore having but a single slide.
The plates used are labeled I'm
Simultaneous" and are tho kind which
photographers use for quick snapshot
work, such as street scenes on rainy
days. They are four by five inches In
size. Having put the loaded plato
holders In the cameras and taken out
| the slides, Mr.. Peters pulls pair OF
cords which open the shutters over the
lenses. The comets image then com.
mences to burn its impression upon the
| plates.
| Whizzes by Forty Miles Per Second.
The comets speed pass the lenses OF
the cameras Will increase to forty
miles per second while son,e of these
exposures are being made. Imagine
your snapshooting an objece moving
past you 1850 times the speed of a
lightning express! But inasmuch as
| this colossal skyrocket will not APP
approach nearer to earth than 10000, 900
| miles. which Is fifty times as far as
the moon, 1t movement is not percepibel
TO the eye.
The length of the exposure varies.
While the comet Is seen In twilight as
now. the shutters OF cameras are left
open only ten minutes, while later on.
| when 1t appears against a dark night
sky, half hour or more Will be given
The moon which VIII intrude upon the
scene during part of the comets period
of greatest splendor, will cut down the
exposure somewhat. The chief luminary
OF night will, however, be in the east
ern, or opposite. side Of the sky from
that in which the great tailed star is
seen.
The shutters having been closed and
the plate holder slides pushed back In
to place. Mr.. Peters takes the plates to
small building near the camera house
and develops them. Amateur photogra-
phers-which now means half the
population--will be interested to learn
how he treats the plates in develop
ment.
Desiring delicate negatives full OF de-
fail he used weak hydrokinone de-
veloper, with plenty of bromide, which
holds back the sky fog due to twilight
or moonlight.
Enlarges 1t Five Times.
Graduall,, the comets head and part
OF the tail appear on the plate. and
when the developing is over they show
M about five times as large as seen
nv the naked eye. The head. 1t is
hoped, will show up on the plate about
the size of q pea when 1t is nearest
earth.
Az to how large the comet will ap-
near at its best, no astronomer can YET
predict. AT its last visit. in 1893, II
was described as measuring from heao
| to tip Of tail a third OF the distance from
| the horizon to the zenith or point OF
the sky directly overhead, while at tne
preyious visitation in 1853 1t Is record
| cd to have covered more than hair TINS
| distance between horizon and zenlth.
This means so many million miles
through the heavens that astronomers
hate 70 think Of 1t. Such bodies seem
10 have gathered more material before
ono visit to our neighborhood than be-
fore another. and their span OF the
| heavenly dome cannot be predicted uh-
| til they spread to their maximum, %
this comet will do May 81. AS to now
It's head will compare on that cate
with the stars which we already KNOW
Il is difficult to predict. Some OF the
government astronomers tell me that
they expect 1t to be brighter than
| sirius. the brightest star of the heav
ans. while others merely say II VIII
he brighter than the comet OF the past
winter. and still others will make no
prediction whatever
1t will be compared with all sorts OF
familiar objects within the next lew
weeks Some who see 1t Will tell you
that it Is no bigger than grain OF
shot While others viewing it tho same
night will declare it to be as large as
a dime or a quarter. The personal ele-
ment causes such comparisons to vary
greatly. which reminds me of q story
astronomers tell of a visit which Two
senators made at the Naval Observa-
tory some years ago. Professor Eusa.
Frisby was showing them plahee
through the big telescope, ana one sen
ator declared it looked as big as
nickel, while the other was quite 3. as .
sure that it appeared as large as q
dollar. Finally they appealed TO fto-
lessor F'risby. who, having TINS Val,a :.
bility of human vision In mind sala J
"Well, gentlemen, nickel woula prop,
ably look as big to one or you as
dollar would to another'
AS matter of fact the senator 10
whose nickel appeared as big as lhe
others dollar was poor MAJ, W. W.
the other was a millionaire. But the
astronomer was too tactful a man tc
4 make matters worse by. explaining ms
A real meaning
The government negatives will be
4 filed away in series and Will furnish
a complete history Of the comet IRON,
4 1.-THE time Of its first appearance until
y its fading completely away late In the
q summer. 1T will become Invisible, tt
\ the naked eye at the end of July, but
\ the Observation-Disclosures Will con,