Crawford avalanche. (Grayling, Mich.) 1879-19??, 1899-08-24

fed to advantage depends largely upon
the perfection of the object glass. In
the Yerkes telescope a glass which
magnifies 3,700 times has been en-
ployed successfully. Through this
the moon would appear as 1t would to
the naked eye at distance of sixty
four miles. The eye piece ordinarily
used magnifies 400 diameters.
ITcredible as 1t seems. the delicate
measurements Of the movements of
the stars are calculated by cobwebs
nicely stretched and forming the real
measuring apparatus Of the microme-
ter. They last for years and are even
cleaned Of dust with a delicate cam
ePs-hair brush. Taking off the glass
covering one evening. Prof. Burnham
was examining the webs. He absent
mindedly breathed into the aperture,
breaking one of the filaments, which
It took considerable time to replace.
At the Yerkes telescope n device has
been perfected for lighting the threads
with electricity and making them a
faint red color. A white light on them
would be so brilliant as to injure the
eye Of the observer In addition to
its micrometer, the big telescope Is
equipped with all other accessories,
such as spectroscopes, spectoGraphs,
spectre photographs, photo photographs,
etc.
While interest centers around the
main dome and its sleepless eye, the
Yerkes Observatory would be big
institution II 1t had only its minor
glasses to depend upon. One Of these
Is q twelve-inch refractor mounted in
the north dome. A twenty-four inch
reflector will shortly be mounted In
the south dome. A sixty-inch reflect
Ing telescope Is also being built now
tory, and will be mounted in another
building ut some future time. AS 1t
stands equipped the Yerkes Observa-
tory cost 100000. 1t Is the most com
plete Ia the world, with a refracting
telescope forty inches in diameter.
Next In order is the Lick Observatory
on Mount Hamilton, with Its thirty-six
inch refractor. and third in order is
the Imperial Observatory at Pulkowa,
Russia, with lens thirty inches in di-
ameter.
tome of the TELESCOPE.
The building Is In the form OF q
Latin cross. the longer axis Of which
lies due east and west. A great nine
ty-foot dome completes the western
end and twenty-six foot and thirty.
foot domes terminate the north md
south TRANSCRIPTS. The body Of the
building Is divided into laboratories
libraries, offices, computing rooms anu
Photographic dark rooms. The ground
floor Is equipped as an instrument
slioI, making this the only ,obseIwa
tory In the world which manufactures
Its apparatus under the direct super
vision Of those who use them. This
gives unexampled facilities for the
application Of new methods OF re
search. and already more than dozeI
intricate machines have been con
structed and used successfully. The
observatory Is built Of yellow brick
ornamented with fiuted columns carvet
at the bases with gargoyles and othel
symbolic devices. The corridors and
stairs are finished In white marble
del.cately veined In green and tho
wood Is OF massive oak.
The observatory has little life Of
Its own. Professors In charge have
built their homes along the lake. ant
n small colony Of scientists has gath
cred about the big telescope. DIR. Hale
the director. has q beautiful cottag'
q short distance away. Prof. Barnard