The Anaconda standard. [volume] (Anaconda, Mont.) 1889-1970, 1898-10-16

the contents of the eye: the cornea.
being extremely tough. is not liable to
injury from the poirt OF the quill Pro-
cure a small camel hair pencil. cut
down the hairs until only an eighth OF
an inch long. and. having charged the
stump with turoentine. proceed to
twirl IL about in the "dish." 20 a. to
remove the last trace of pigment. Ex-
anime under a pocket lens. and. IL
clean, melt out the cornea. and with a
pair of fine scissors. trim OF the
turned-up edge of the "dish," retaining
only the --LATEST part at the bottom.
Soak In turpentine until any IA that
adheres Is dissolved, and o have the
lenses for your camera. but the disc IL
not fat.
To fatten It thoroughly IL an easy
matter. 1t should be done In this way.
Get a very thin cover-glass. see that
1t Is perfectly clean. and then place
IL upon a hot plate. Next melt a guam
tity Of anada balsam. n with a
needles point place q drop about the
size of a pin head upon the i've glass
beneath the cornea- Place a very small
disc of paper over the cornea. set over
the a glass slip. n weight the
latter down with coins 80 as to fat
ten the cornea. The fiatness Of the
cornea a be seen by the spreading
out of the bead of balsam round the
margin of the object. When II IL nat
let TIE WnOle cool.
The under side OF the fattened corner
will then De cemented 10 the c~overgiass.
and the "facettes" will be simply plano
convex lenses, since their inner con-
vexities, being imbedded in the balsam.
will cease to exert their optical proper
ties to any appreciable extent The
mount can now be examined under the
microscope. Put in a half-inch objec-
tive. and, IL IL has a screw collar, ad-
just for an uncovered object. Use
a low power ~eye-piece of about three
diameters. Stoop down the aperture
and bring the cornea into sharp focus.
BY a solid cone of transmitted light q
~hexagonal figure will be seen forming
the boundary of each facette. A num-
some insects. n Ii is in the angles OF
these ~hexagons hat the hairs have
their origin.
1t will require some nicely of illumin-
alton, however. to disclose the Tens"
in each Of these divisions; the solid
cone of light as usually transmitted
by the condenser fails to reveal them.
Remove the limiting diaphragm from
the back Of the condenser and insert in
its place a patch-stop that Will give
background illumination with the OBJ
jective employed. having previously
stopped out half the annulus with a
strip of black paper. Use the plane
mirror. and. with the condenser in TO
Gus. this semi-annular beam of light
will fall obliquely upon the object and
the "eye-lenses' will appear in bold re-
lief.
The next step is to % the Ter
made by following the above instruc-
tons. A small slip of wood, through
which a hole has been bored, should be
selected. The cover-glass containing
the eye-lens should be placed over the
hole in the wood and fastened in place
with a gum-backed label. The cornea.
being under the cover-glass, cannot be
injured. The lens should then be fixed
in the camera in a horizontal position.
The centering and focusing will be un-
derstood by any n acquainted with
the internal arrangement Of a camera.
The camera will then be ready for ex-
Fermentation. 1t has been found by
those who have successfully accomp-
lished the work of p~hotographing
through the lens OF a 1y's eye that 1t,
is necessary to make a very long expos
ure, in some cases as long as three
hours being required. With a camera
the lens of which is mad from the eye
of-a dragon fly constructed In the man
ner described. perfect photographs have
been taken OF landscapes, figures, and
even small objects like table orna-
ments and fittings.
Nature seems TO have beer particu-
larly lavish in ~bestow'ng these lenses
on Insects. 1t is a fact that from a
dragon-fy's eye there have been taken
from Is to 1000 perfect lenses. so small
that a million of them would not cover
a square inch of suffice and yet each
capable of yielding a recognizable Pho
tograph.