The St. Louis Republic., 1905-12-31
RErURl.ic SPECIAL.

New York. Dec. 31-Harvard College Oh
servatory IS al present ensaScd in mount
; 9 s'Sty-inch rejecting telescope recently
purchased from the estate Of Doctor A.
A. Common Of England. which will be not
hut the telescope Of greatest aperture I'm
! active use In the world.
For. while the Yerkes Observatory Of
M BAY. Like Geneva "a wis.: also a. has - ::s,y
inch mirror. for want OF the requisite
means u has not vet been mounted nor
A. c"mmos. on o the other M hand eUes "a. .. sue e:
cesfullv used bv himself thirteen years
ago. so that there Il little doubt Of II sub
sel'sent usefulness In Cambridge.
Very soon after tho purchase Of this
telescope bv Harvard Observatory last
year si"is were taken Tor mounting it IN
Camb fice
The site chosen n near Garden street. On
the eastern slope OF the hill below the
'nain building OF the observatory. and hid
den hv this Form the view of the other
Sod was turned September q isea Tho
small fwo-s;cry wooden building that ad.
toins the telescope Is now practically COM
p!e;ed
In the second story Of this building Il
the obse.vinF-room. In which Wiil be the
eycpicc" os tho telescope and numerous
",,nr smS cnmiroIlnr ;hs " sn.se,.rs 70. n
the ground hocr Is room which II 70 ha
ftt'e': with all necessary appliances for
stiver'ne tho great mirror and for ham
mechanical arraneement. the end Of the
iro. tuh. which supports the mirror can
2. Sso1shs close S e sn epee;ee vh,sh 81
verin~ room. and through. which this
massive disk Of eiass-nearlv . ton In
wcieh:,will BE- rolled IN o. r . kind OF
necessary to b recover : With . fi!m Of
The cons,rucs,on Of sh,. building and
beine carried on in accoriance with the
rlans ard un!9er the direction OF Mr. vii.
lard p. Gerr:sh. Of the observatory. The
tas., 81 ,no,snt:n: the instrument. In itself
an Intensely Interesting operation. holds
special attraction for one who n inter.
ss.ed IN mechanical engineering. The
mounting ~ great equatorial such A.
sasls In these moieYn DAYS II has passed
from the domain ~ the instrument maker
to that o: tie engineer. who finds abun.
ssn. scope for % inssnu.tv. and sechin:a.
construction with very delicate mechan-
iesn,. for not only must the pondeYous
from fuhc that supports the mirrors b 20
eo.ufe freedom from tremof hut the
mechanism which guides u must have the
greatest ease and delicacy Of movement.
combined with facility Of directing the IN
INGENIOUS pEvlcES
The method Of mounting the Common
teiescci" At Cambridge Il IN many re-
syecfs the sane as that used for Il in
Doctor Commons observatory In Ealing.
England. but the manner Of operating and
controlling II here IS entirely new. This
FMS; r1linent. instead OF being supported By
unin. as are many of tho large telescopes
At various observatOrtes. rests upon q
cylindrical steel float eighteen feet long
and seven Zee; eight inches In diameter.
~ =, e. Ssa
with water. and Is 80 oalI:ts,ed that ats
sAis points toward the celestial poi.
Delicate pivo,s Ga the ends Of the fios.
serve 80 steady l; is this position. allow
cf nearly ito en,!,e weight hy the buoy
!IE effect OF the water. Al tho upper end
o' 81" roa; Is ~ stout fork-fwo sfee! pro-
1~s,.ons securely baii.t into opposite sides
If the foat-tn which swings the t"ls.
scope proper. n rectangular tuba or ssruc-
tnre twsnfy-ono feet six inches long and
six feet square
Tie lower end cf this structure for Q
distance oe xsA feet - Of steel plate and
supl or;s the mirror. The remainder Of
q. the tube consists Of q iigh: framework
OF ane!e iron covered with canvas to Sc
the necessary !iE;!!'y. small mirrors
supported at different points along the
axis o: the tuhe servs TO reflect the Image
formed by The great mirror up to She sta
t;cnary "ysriece in the ossef. ing room.
Tho attention Of the visitor n. the size
or 10 rev telescope - FIRST attracted 20
the big tank. which IS projected BY a high
fence o: matched boarding from ihe curl
Gus Investigation of any stray :aieS or
email boy who C9igh. find bis way there
4 cs.ls!!!A" hole it 's. with "A bottom that
:nciiaes upward az az a.gis o: about forty
rye iAgr.es. ana wallis o: solid concrete
To cons-r1:c: this .snx q large excavation
va, made. fifteen zee; deep a, .he further
end and at"u: ;werty-cEs feet in length.
With p.rpe6!ctlar sides
\ mold vas then maze of s:nlbeYs and
riarks s4iai 30 'ne intended ir,ef tsne1-
-iSYs - he tank. ai3 sGs:en,isi i.t '!"
hole by means .: Wooden frame work
ward sof. concrete -ss pCs.rsd into -i.'
space srogrt. ard h.n.at and allowed. 20
harden. forming a sc,id. irnino.ab.c b@ss
TIE raii. have Uniform thickness %
eighteen inches. thr foundation ~ ,he
Deeper rni Of TIRE ,srx measures siS fee:
i!i c.rc!e;e. sni here shs Pivot at tbs lover
END q the fSs'. OF which the latter Nil!
.urn. has been securely embedded, sha. .:
:he srosr ed hSlrE attached 30 All iron
franz. which 3. turn - attached 20 sA~
concrete vail a. the shallow end o. sas
tank T'he- foe; IL ~a'e: tight. the only
o;-srinr ss;:S a vsAnhni. .: tie gpcer I'D
erea. holiox cyiinser, :: recsSAA:y. TO re-
pair H.
HELD By BOLTS AND RivErs
n.se~ 90 "a perfectly each into i,s sp-
;.o.c,e1 yiArc vhsrs Z. Is held f'.r,!y by
.'rorS bolts and r!s..s Fer - iS.gs \
Instrument :; is scmA-kahly simple sas In
2ad careful sfssy and experiment on :se
par o. 81. MAKE. Doctor cor.M,s TIE
:tea ~ s2pYoctIzS :ae Solsr axis sn . :Aaa
c: Wa;sr a. h-@' S.ss ..:o sRss. and per
esp~e.si.y practical ons- ~ao~e simplicity
a-A ssS1l.Gv ~ Yco-Ne.rS q Sar0o sceecV-