Walker Lake bulletin. (Hawthorne, Nev.) 1883-1926, 1897-11-24

EN- with reference to obtaining not only Il
clear sky, free from dust and smoke and
electric light. but also a spot free from
vibrations of the earth. The instruments
of an observatory are so delicate that the
jarring of the earth caused by a passing
wagon or train may put them out of equi-
poise and require a readjustment. The
observatory is called Chicago institu-
ton, but is, as n matter of fact located III
Wisconsin. at the head of Lake Geneva,
seventy-fye miles from Chicago large
area of ground was purchased and laid
off in such Il way that there should be no
roads in the immediate vicinity of the
building. The nearest railroad track is
almost two miles distant, while the clos
est electric lights are seven miles. The
instruments can easily be protected from
electrical disturbances, but the shining of
an electric light in the sky is source of
serious embarrassment TO the observing
astronomer, for a bright illumination close
at hand nullifies the power of his instru-
ment when observing the stars. Thus 1t
will be seen no pains have been spared to
perfect all the conditions favorable to the
astronomer and the great fortune which
has been expended in fitting out the OBJ
seryatory has made it perhaps the most
perfect on the planet.
The main building is $50 feet in length,
or more than one city block, while the
two Is are each 160 feet. The dome, in
which the great telescope is located, is at
the further extremity of the main build
ing, while at the ends of the LIS are small
Pr domes for telescopes of less power and
other instruments. The building in which
the great equatorial is suspended is COW
cred with an iron dome 30 feet in dame
ter and 60 feet in height. The tube of
the telescope has length of more than
go feet, aud is hung upon supports whose
foundations of solid granite sink deep
into the earth The dome is placed upon
thirty-six wheels, each yard in diameter,
and is moved in any desired direction by
machinery, while there is a movable floor
which, by very clever mechanism, can be
made to rise or fall so that no matter at
what angle the telescope may be set the
observer can stand ON the floor to do his
work or seat himself in chair, lifting
the floor from time to time as may be nee
essary.
The uninitiated should understand that
Wneu n telescope Is HAtu upOH sur lHe
instrument does not keep the object in TO-
Gus more than a minute, unless especial
provision is made for moving the telescope
with the apparent motion of the star. The
star really stands still, but the motion of
the earth upon its axis is constantly plac
ing the telescope out of focus, and, there
fore. means have been devised by which
the telescope can be moved at a rate equal
to that of the apparent motion of the star,
SO that when the object is once in focus
and the clock work which moves the tele-
scope is started, the instrument will fol
low the star from dark until dawn, thus
giving ample time for observations of any
length. As in spite of the wonderful me-
chanism used in the work large telescope
is not easily moved, the star to be obsery-
ed is first located by means of the find
err n much smaller telescope, and the
nosition in the heavens of the object be-
ing ascertained the great telescope is
moved according to the scale of a gradu
ated circle placed just beneath and an
exact focus is obtained. The Yerkes tele-
scope is fully equipped with every modern
invention, not only for observing, but also
for recording the observations. Photo