National Republican. (Washington City (D.C.)) 1872-1888, 1873-10-27
THE MONSTER TELESCOPE.

HE MONSTER TELESCOPE. |,
tContinved yrow First Pues.)
nth him, which lasted as long as Mr.. Dawes
wed. In 1858 Mr.. Dawes purchased tele-
cope from Mr.. Clark, which was 80 satisfac-
Org In its performance that he soon ordered
mother, which, after having been completed
y Mr.. Clark, clipped from his hands and
nut to test 1t. He, however, duplicated the
Ilass, and forwarded IL to Mr., Dawes. In
$50 the two largest refreshing telescopes In
he world belonged TO the National obserya-
ory, near ~. Petersburg, and to Cambridge,
md possessed object glasses about fifteen
inches each In diameter. In 1850 Mr.. Clark
completed one eighteen and a half inches In
And this was sold to the Mississippi university |
In 1853, but the war broke up the university |
and the glass was purchased by the Chicago |
Soon after this Thomas Cooke |
4 Sons made glass Of twenty-five Inches
aperture for X. 8. Newall, OF Gateshead,
England, being much larger than the Chicago
telescope
TELESCOPE GLASS,
The difficult art Of making the combination
Of Grown" and flint" glass and casting
rosgh discs OF the necessary purity for OBJ
joct glasses has "a yet been brought TO Its
highest perfection only In England, and even
there only single frm could be relied ON to
furnish glass discs OF the necessary sinc and
4 CO., Of Birmingham, England, from whom
Mr.. Clark had procured nearly all his OPP
teal glass during the twenty years he had
been making telescopes. As soon rs the con-
tract with tho Government was completed
Tor tho Warrington telescope Georgc u.
Clark, the same who melted tho bell In the
kitchen nro twcnty-seycn years before,
crossed the ocean and Proceeded e BiTming
nam 10 contract win finance " GO, Tor the
glass. Making discs OF tho required size
proved TO bea task OF such difficulty that
more than year elapsed Oeiore onuie sue
cess was reached, number oil trials having
failed In the meantime.
The glasses, sowevcr, renchcd Cambridge
IN DcccmScr, 1911, and cost IN the rough
ABOUT so'oVV'
TESTING THE GLASSES.
AS ,ne hrst payment Oh toh thousand uol-
iaIs was quo ~ soon US tno g.asscs, WIZ
toed, INC lesh NGe ~ once prococosd witn,
an9 were maac ny ui,ect oPt'cal cSnnnnh.ion
ana Gy pomIhca n.nt- i1 Apply ,ne nrst,
snc Blass Mas &c. w w Ns c1gc uctwecn
nrm supports IN inc mlddic OF aiarge, nearly
Gark toom. iamp was SCI az one Gnu Vi
me room, SO Us 70 snlhe upon inc baek sur
ace OF ne e'ass ~ rlsnt angles; oen'h a ,no
Rnass was p,scea large lens OF enort FOCUS,
so nat tne nBnt OF uie lamp Pesseu tnrougn
potn tne iens anu TUG u,ec, anu cauno W u
locus ~ ABOUT m equnI uistshce on tne otncr
slue. ING oyo pemg p,acou eAaeuy ,ni,
,ocus, ,nat poIuon OF he slnss u,sc p ,,,s,
oy INC lens appeared ~ oiiilxnuy ,lluni,,
mated surface on which the slightest defects
were mhgninea IN lattnnY dogfee. rue
minuts1 spechs, puomes sno scratenes up,
peaIou ~ mug uoior,n'ucs, hnu any ven VI
unequal ueneLy wou,1 aPpcer hsn wave ~
Ins priSnt SURFACE; nc Pfac.'ccu oyo VI ~.
eioer Oiarn soon de,Getou sucn y "anc.
tnat " he gus, no ehsrsunca, woulu
not give penny Iot " Inc apparent de'
feSt was soon seen py All.
Inc ,mpoI.ant ancsuon was wne'ner y wa
10 inc inteiior o. he g,ass OF on 'he SURFACE.
10 settle this US Posiuon was marked oy
pasung pointed str,p OF paper on the glass,
and tue lamp was moved 70 que sue SO Us W
shine through the glass obiiquciy, and inc
position o. the wave was again examined.
II, In the interior OF the glnss, IL would seem
to move away from the paper point In con.
sequence OF paralax; no snch ehange OF
position waspersePuoie, showing tna' tne &c,
iect, wnatevcr " mi1nt DC uiu not cAtenu
| INTO the lnterloh. ShreIui examination
showed several other ines OF INC same sor,,
but inc Test inalcatca mat thoy were NJ
on the same surface, ana would ,hcrviore po
rsmovee 10 ue 0PeIauon OF gr,nong w
giass. ~ was sun OF lntcrcst 70 Iearn VIM VIM
thsy reany were, ana . careful shMhina.lon
showed mat ,ney We,o onIy seul1en'ai na IN ~
OF INC srinuns .oom useu w onshes ~ ~,
70 give IN even surface 70 INC slas, Mhieh
hsI NOT oeeu enufely ISulo,ou ny .he poishe,
Inns hrst tcst having neon successful on
o0th Yissscs, mat ~ polMnca ngn. MAS ~
piled. Hearers Oh PROFESSOR iyndans rec,
lures last Winter may ic ~ al1s now, oy
slmPiy summing plcec VI shss W p rstv A.
WINE poisriked nsnt was passing tnrouSh y,
nc was apie 70 enanse w. aes n.p. gu ne msn,
III icnnrkaoie manner. lnis prvpeIy .,
poiarzca ,gh. snoiEs .hc nnIss oo" ~ s .eS
Of inc squA anneaiIng o. gins, 10 ~ hpp.
tne Jest thc glssscs Merc lnhen in.o Wy opel
Az, sna laio on tne gLouna up0a pesG -
oIaek clo.n. Each Rinss VI .hIu ',o~ 800 !.
euch AWAY mat inc ngnt o, tnc ny OF elouu'
shouid DC renectcd from lts unoer surIaGc
and reach nc eye a,ter M ,s traVGrslng ~
snchnessi ins hSh' Nus ,iem s savsn
Ncd prism he,o IN Lnc MANU- snu .urns,
rouna ana rouna lug glass a,s !. oeing .urne I.
Iouna 30 tnat my ngnt snouia DC ehan,inea u
Al eirections. NY rusu,t inulca'cd IN. ~, ~
mint giass was perlcc.Iy uniiorin, Mhiic ~ w
sroNn 'heIe Mcro WY snsn. sns'oo VI o. M,
rom INC centrc 70 tne Sucum,ercuee, III
ueIect wouhu not intefnio WIN .no ussiu'
ness Oh INC glass, anu; cuIi1usy enousn;
ulsAppearca uuris une Ena'nS. ~ .ha
Wnon tne lenses were SolhPietca ho uaee
unequal hnncailnB couiu oc socu.
Il III