Richmond dispatch. [volume] (Richmond, Va.) 1884-1903, 1894-12-13
ABOUT ASTRONOMY.
The Aids BY Which Such Remarkable
Progress Has Been Made.
PHOTOGRAPHY AND SpECTRoScopE.
what rbesc Grand Instrumentaiities Havs
Achieved-The various Kinds ana
Sizes Of Telescopes.

no the Editor OF the Dispatch:
Tsa r,sspatch is entitled TO credit ana
vhanks for the attention when !"
columns bes,ow, from time to time' upon
she subject OF astronomy
,rh,s sublime star-iaw is the most an
.,.r, fascinating. and eievating OF the
,c,cnces. whilst II is at the same ums
.,n,nently practical II is just as usei~
ma a clock. an almanac. or floating snip
Ird.ed what would navigation be without
az .rhe oceans would still be raugh'
,v,,h ALI those terrors with which they
ware once invested. and which the ceie-
brated poet, Camoens. embodied IN 'ha'
fhghtf,il monster which he Imagined W
IN stationed at the Cape or Gooa hope
a. deter the daring Portuguese mariners
80, ,crt,rinc on those untried waters
PROGRESS OF ASTRONOMY.
=. eo,nnaratiyely recent years this
,ranoh ~ lofty learning has MADE re.
,asrkahle and delighting progress: Mos'
~ mis- has been accomplished Win .he
aia of enlarged refracting telescopes w.
row the grander refiectors w.l Propaois
assert their supremacy. But teieseops"
s 49, not done the wonderful WORK:
g., have had the marvellous AID OF
,ho,oeranhy and the spectroscope. lnese
,hree grand instrumentalhes nav
achieved for astronomy wf1at the ha,i'ine nm,
the blow-pipe. the crucible, the saNanie
battery. the microscope, the stethescope'
ac,Ss The scalpel. and expert manipuia-
&C., have done for chemistry, mineraiosg'
and other Sciences.
HONOR DUE TO OUR COUNIRi'
In This most gratifying progress our own
,n,,r,rv has borne a highly honorapie'
80 in some respects, a leading part;
Ter her sons have greatly distinguishes
Themselves as makers Of the finest ins'ru.
,nents as observers, as discoveries ana
ss caiculators The noble and favorl'e
science of mathematics finds It's hleh.s'
aunlications among the ceiestiai oiua.
,rhe scales and scaling ladders OF the
human intellect IL climbs up 10 those OiDS'
weighs and measures them
TWO KINDS OF TELESCOPES
The two leading classes Of telescopes
pre refractors and refiectors In the ioI
mer YOU look directly through siass a.
the heavenly objects. In the natter w
look at them as they are rehectea rom
n mirror. In the skyward end OF theI'
ferent refrangent power in order to pre-
cent urismatic coloring which consul
,ute the object glass. Through TINS OBJECT
glass the light comes from the iuihihai!
under observation, whose inV1teu Hnae
&c formed I'm the focus or tne ooJer'
glass near the earthward end OF the tupe'
irbere the observer examines that image
with strong magnifying eye-Pieees
INHERENT powers. some magni1yins /. seN
.rai thousand times. Both reffactors anu
rs0ectors are mounted equatoriafy, when-
-. n,,cticable as they can then sweep
the whole armament. But rehectors nave
hesn ,nade of much larger size IMAM re-
fractors and the difficulty OF mounting
,beu comfortably has been weiI-nigh
insuperable. But of this more anon VI
course. the observer has to follow ms
,ve-piece and has to go up, or down, ac-
oording TO the direction Of his tube. ms
Inconvenience has been partially opVi"'eu
nv the use OF mirrors which IN soii'c
cases. turn the light into the tuDe' anu
in others to the eye-pieces.
THE SIZES OF TELESCOPES.
When Nesgrs. Alvan Clark & Son. OF
Cambridge. Mass, finished those TWO ~,
inch refractors which are owned py GU,
National Government and the ChNeIsI''
~ Vir.fnia. IL was grar.l achievement
Russian Government whose object-glass
has a diameter OF 90 inches, and one LOT
the Lick Observatory. in California OF %
inches. and now they are testing the
lenses of the Yerkes telescope. for CHICAGO
Of 40 inches diameter. The hope Is IN
duged that rcfractors may be carrleu w
10 oblect-glasses with diameter Oh w
inches But every enlargement or DIANE
ter increases the difficulty OF procuring
suficlent masses of haWless ana hohho-
geneous glass. and Of forming them lhto
accurate lenses. The weight OF opJee'-
classes and of mirrors causes uahstI
OF warplng and distortion IN many oil the
positions IN which both retractors ana re-
Electors have 10 be placed In using theih,
II Is an interesting fact that one of the
f-Iarks I'm testing one OF their fine In
struments. though not of their lafse
class. discovered the companion OF the
brilliant dog-star, Sirius.
The only telescopes l have ever been
rermitted TO use have been refractors
The largest was that at the UNIVERSITY
NJ Virginia. Professor Hall once granted
me the exceptional privilege OF examining
the satellites of Saturn. through the equa
telescope in Washington; but bad weather
for several days prevented the great pea
sure Lieutenant NJ. +. Maury dellghtec
me even with the old 9-inch instrument
which the observatory possessed when IN
had charge of H.
THOSE which | have most enjoyed were
the l-2-inch German instrument at I'M
State University of Missouri, with spec
troscope also attached, and splendid
one OF u inches, made by the Clarks. a
the Morrison Observatory. near Glas
cow. Mo. We chung TO IL one bright win
ter night when the thermometer wal
several degrees below zero. No fire is al
lowed where those delicate Instrument
are operated. Occasionally we ran off 4
a distant room and warmed up for re
newed delights. / have heard OF on
small private telescope In Richmond
Some years ago my friend, Kober
Howard. clerk of the Hastings Court
possessed one.
IN REFLECTING TELESCOPES
the open end OF the tube is pointed 10 TIT
sky, the light descends TO Its bottom
where the mirror reflects the image to III
focus, near the top, and there, on IN
sides. that image is examined with IN
magnlfying eye-p!eces. The largest re
Rector In the world is that constructed
by the Earl OF Rosse. In Ireland. abou
fifty years ago. Its paraboiic mirror. Of
speculum, Is feet In diameter, and II
made Of alleged metal. highly polished
OF course II is very heavy, and was hunt
on chains between two walls, and had I
very narrow range, which greatly i'm
paired its availability. 1t may yet b
brought into play by being hoated OF
water.
But Sir Howard Grub has succeeded
In mounting. equatorlally. In Melbourne
Australia, reflector OF feet. and DR.
Common has since mounted one thus o
feet.
SIR WILLIAM HERSCHEL AND LIE
VERRIER.
Sir William Herschel greatly distin
guished himself after he was 40 years OF
age. both IN improving and In efficiently
handling these star-gazers. Probabi,
most OF his best work was done witt
his 20-inch reflector. But ne had one o
Nbout forty-eight inches, which proved 81
snwieldy that IL was dsmounted. anC
30 placed that the heavens could no
peer into 1t. On one Of his natal anniver
varies the surviving members OF hi
family held memorial gathering In III
tt xsha ~ -