The Washington times. [volume] (Washington [D.C.]) 1902-1939, 1903-10-11

T oUIs GATHMAN. mechanical en-
gineer Of this city. is the inven-
tor Of what is called the sec
tionaI-Isns' telescope, which promises to
surpass anything yet made in bringing
distant objects nearer to the eye. If the
ideas of this inventor can be carried out,
IL will not be long before a telescope
will be constructed with a much larger
object glass than any now in use. and
such planets as Mars, Jupiter. and the
moon will be far better known than is
possible with the Yerkes or the other
big instruments set up in recent years.
Instead Of huge object glass made OF
two pieces OF glass. which by different
degrees of contraction and expansion
render them useless except under the
most favorable atmospheric conditions,
Mr.. Gathman's telescope viii have an OBJ
feet glass Of many small lenses so
mounted as to focus at a given point.
and so arranged as to increase the pow
er of the telescope many fold In short,
the capacity Of a telescope made accord
ing to the plan pursued by Mr.. Gathman
will not depend upon the size of the OBJ
ject glass, for that is practically with
out limit. but upon the capacity of steel
tubes and accessories to support ana
manage the glass.
One of the views shows an object glass
for a telescope drawn TO a scale of ten
feet in diameter. II contains. as shown.
a large number of little lenses, easy to
make. and set in brass disk. This is a
correct representation of a telescope al
ready built by Mr.. Gathman of small ca
pacity. but # shows how the sectional
lens IS constructed.
Optical Principle Involved.
The sectional-lens Is a mechanical re-
production of the eye of fly. Instead
of one large pupil it is made up OF many
to guard against injury, and to magnify
everything seen many diameters. The
small lenses are perfect in themselves
and are constructed on the same princi-
pies as the big lenses. That is. there is
piece of flint glass and OF crown glass
side by side to correct refraction O,
light. The small lenses. according To
weil-known law OF optics. nave little or
no alteration. hence one of the chief
diinculties of the big lenses is overcome
oy the MECHANICAL expedient of using
many little lenses for one big one.
One of the chief drawbacks of the "a
Ss and 30 inch telescopes that have been
MADE is that they cannot be used on
cold nights in winter when otherwise the
best conditions prevail for making OBJ
servations. Flint glass and crown glass
DO not contract in the same proportion
and when the object glass of the Yerkes
telescope. for example, is pointed out Of
the great dome. when the mercury is
~ degrees above zero. the contraction
or the outer lens is so much greater
than the inner that nothing can be seen
through it. With the small lenses the
contraction is reduced to such degree
that this difficulty is overcome, and the
Gathman telescope is as available on a
cold night as upon any other.
MI Gathman has constructed the tele-
scope shown in the accompanying view.
and uses it nightly at his home. 1899
Vernon Avenue northwest. It Is a small
instrument as compared with that in the
Naval Observatory. on the other side
OF Rock Creek. 1t shows. however. some
marvellous things. and il is strange that
bis ingenious device of reconstructing the
eye OF fly into the object glass of a
telescope was not undertaken long ago.
Jupiter looks as large as the moon in
this instrument. 1t is a glorious body
when viewed through this telescope, and
one cannot help wondering II the Al
mighty has in his wisdom placed other
creatures on that distant orb. Mr.. Gath
man smiles as the question is asked, and
he explains that the density OF Jupiter
is much less than the earth. and that it
is not in condition for habitation, unless
the surface Of the planet is entirely diff
ferent from what we suppose it to be.
Miss Proctor Tries It.
Mr.. Gathman has not been successful
in having astronomers examine his tele-
scope. He thinks it strange that men
engaged in the study OF science will not
so much as come to see him. to ascer-
tain by actual experiment whether his
instrument is better than another. They