The Wichita daily eagle. [volume] (Wichita, Kan.) 1890-1906, 1897-09-14
TO EXPLORE SPACE
WHAT THE YERKES TELESCOPE Is
EXPECTED TO DO.


| Biggest and Best Star Chaser In the World.
and Not Only the Biggest But just
Abont IS Big a. It's Worth While to
| Build Them-some Things That It Can't
DO, hut More Things It Can-Csn't
See the Man In the Moon, Even II He
Is There-whsre and What the Big
| Glass Is.
| Chicago. Sept. 13.--Chicago has the sin
| gular distinction Of having twice posseee-
ed an astronomical instrument admitted
| 10 De the biggest refractor and justly en-
| titled 10 be called the best telescope CT
any class in the world. The equatorial
Of eighteen and a half inches aperture
and .wenty-three feet focal length which
was mounted in the Dearborn Observa-
| tory in this city in March, 1856, led all
| the rest" from that time I'LL 1873. when
| two lager instruments by the same maker
were finished for the National Observa-
| tory in Washington and for the Univer-
sity Of Virginia respectively. Now the
lost lead is retaken by the building Of the
| Yerkes Observatory OF the University OF
| Chicago, near te northern extremity OF
Lake Geneva, in Wisconsin. The struc-
! ture is equipped in part with monster
| giesS having a clear aperture OF forty
| lncnes, mounted in a steel tube sixey-
| two feet long. The diameter Of the open
| ing is one-ninth larger and the light
gathering power nearly one-fourth great
er than that Of the celebrated Lick tele-
scope situated on Mount Hamilton in
| California, and which for several years
undisputably stood at the head Of the
| list.
ADVANTAGES OF THE SITE.
! True, this magnificent instrument ie
not located in Chicago, nor even in the
state Of Illinois. but there was good rea-
son for the selection Of the site chosen,
| and the distance of less than eighty miles
| from the institution to which the obser-
vatnry belongs is not a great practical
| difficulty since the advent Of the iron
| horse and the steam boat. The region is
one where the mean annual cloudiness is
| low for this pratt OF the United States,
| has nearly the maximum Of dust, and is
not likely to be disturbed by the estab-
| lishment Of factories, while the summer
residences on the shore Of the lake are
| we'll removed from the site of the OBJ
| sarve.ory and it is the opinion OF Pro-
| feeso- Hale that # the present number
Of residences were doubled or trebled the
atmospheric conditions would not be ap-
| - Iva 4
| track is more than a mile distant, and
| the shore of Lake Geneva is about a
third of mile away, while Lake Mlchi-
gan is thirty-eight miles to the eastward
| The center Of motion Of the big telescope
| Is $40 feet above the surface Of Lake
| Geneva. and some 1000 feet above the
sea level. The nature Of the soil is favor
| able to stability, almost a minimum OF
ground vibration being secured, and the
| site IS about the least affected by atmos-
pheric disturbances Of any near the small
| lake. as the prevailing winds al the OBJ
servatory do not blow across much water
surface Hence, the atmospheric tondi-
| tons are really good. They are far bet
ter than those at Mount Hamilton, and
compare we'll with those in the neignbor-
| hood Of any other observatory in the
United States, with the possible excep-
| ton Of the one in Arizona. The air gen.
orally Is calm, and an ingenious applica-
ton Of cotton sheeting to that part Of the
"s:it" which is below the object end Of
| the telescope permits the instrument to
be ken perfectly steady, even when a
moderate wind is blowing outside. Crit
| ical,y speaking, the atmospheric condi-
| tiCns for work on The sun, which neces-
sarilv is prosecuted in the day time, and
hitler to has formed the principal sub
ject of Professor Hales investigations
are about as good as could be desired
while those of the night part Of the
| twer.y-four hours are somewhat less
good, the latter fact probably being due
TO the propinquity of water surface.
| CONDITIONS FOR ACCURATE WORK
These points are mentioned rather
| prominently by the writer, who visited
| the observatory last week with the ex
press wish to ascertain the probable char
acter and relative value Of the work
which will be performed there, because
| they enter largely as factors in the an
| swer to the question. 1. is well known
70 the working astronomer that given
condition of the atmosphere at any stat
ed time often may be made available In
| certain kinds Of observation while un-
suitable for Others but that stability OF
| the instrument Is the first and creates
! consideration after the instrument Itself
| has been secured. Better work has beer
| done with relatively small telescopes thai
could be kept perfectly steady than wifi
| much bigger ones which are unstable ow'
| ing 10 poor mounting, or poor location
| both. The bigger the telescope the high
er is the ma gnifying power that can b'
| employed, other things being equal Bu
| evidently the trembling Of the instrument
is magnified in its effect in proportion
y the magnifying power used. and thi:
will lenab the Impractical reader 10 un
derstand the statement that the highes
powers can only be employed when see
ing conditions are as nearly perfect a:
possible. which a. many observatories il
but a few hours in the whole year.
II needs not 10 enter upon minute
description OF the big telescope and 1t:
appliances. Suffice il % state that tn
instrument. will be moved in every direc
ton by electric power with the least pos
sible expenditure OF human force or los:
o. time on the part Of the observer. Th'
clock work which is designed 10 carry III:
instrument round at the same rate as th'
objec4 observed seems 20 travel (this mo
ton being due % the rotation OF th'
EARTH works continuously, as long a
may be wanted. and even the winding
up Of tae clock movement when needeC
* -1a--7-71aI without changing nv 81
muca. apparently. as a hairs breadth
tne position Of s.a- with respect 70 II:
wires" in The focus which are used q