The sun., 1894-03-11
ASTRONOMY wIrn a MICROSCOPE.
II G.thm-n 4. Right We May See the Hairs
on the Head ofthe Mas In the Moou.

on th. Head ofthe Mas In the Moop.
From n, Chicago Dnty Trbure.
For $50. 900 will undertake to construct q
telescope with an objective ten feet in diam
eter better in every respect In proportion than
the forty-inch $500 900 Yerkes telescope and
to finish IL sooner For a proportlonately
larger sum will undertake to construct q
telescope with an objective 100 feet In diam
eter more efficient In proportion for every sci
entiho purpose than the Lick or Yerkes tele-
scope. There lie no reason IN telescopic science
why we should not see the inhabitants Of Mars
and see to pick up pin on the m oon."
This is the bold but intelligent utterance OF
tronomer. scientist, and inventor. Of the North
Side Mr.: Gathman has for twenty years been
ment could be made In telescoplc lenses, espe.
cially in respect of size His doctrine is that
existent thing that thing, can be discovered
Accordingly he has chafed good deal under
ultimate size on account OF the i'm pos sibiiity
Of casting large pieces OF glass without bub-
bles. as well as the other infrmities insepara-
BILE from glasa n large pieces. His dream has
always been that lens could be constructed
IN sections. Two years age he COMPLETED his
that time he has kept hia discovery secret in
order to secure his patent rights. first in Ger
man ian patent has been issued. and as his Amer:
ican patent Is as good as secured. he has had
sthmsn sGy is byre tina.
lens that is made In sections can be made as
correct as any other lens. provided the sec
which prevent an Intsrrefection Of light from
their margins. The sensitiyeness OF a lens
single air bubble. however small In a lens.
however large. renders 1t worthless: the rep
rays V oi Iirht and causes confusion al the focal
point Mr. Gathman,s theory is that L the bub-
PIE i' sorcd out and the Gpening ed s With
again. but he thinks there Is no use going to
this trouble when lenses can be made In small
sections and q the e perfection OF each section as
This principle has for many years been ap-
iiaSt reeetors. but refieetors Of T REJECTING tei
sssopss sOnstrSSetsd S d In sections; =, ho These
sHD.s,s'd that the principle sIs,,Ips were rp;
d pafstysis WortSIess But I estislsns % and iV az.
tronomers were SO we'll satisfied d priori that
tsyP &: sas
shI va: I'D oas os si 9s:s ssS
sSrfsss.s s sO;;.Wesa the :sctiS.: q j., She isnss:
hs 'r.sa nS ' dstSSsn divIdea 81:
lenses Into wedge,shaPsd sections with
tion OF a '6iackened. metallic rim half an
% found It W better to leave wide openings between
the sections the object being to allow q free
temperature ii in 'front.' and rear oi the e iens' and md
In that way prevent sweating In this way he
Tss led to make & the sections S circular @ and Of q
observatory Is made on this plan. It has a cir
cular section In the centre. six circular sec
tions Of the same size arranged around It. and
then six smaller circular sections In the trian-
suit is that objects seen through this telescope
are brighter and better defined than when its
This last lens Is apt to produce tho impress
sion that 1t Is an sssemblaee OF small lenses,
put hs wSsd BE- sSa and
large tense; and that fact makes one curious
matter Of Of NO ' difliesity &r. Gsthnsn @ tax taxes
In any plane. so as TO- see whether they % are
perfectly translucent. Then he gives them
WRs desired Is nGs posTs sns
melted SULPHUR between them. When the
sulphur has hardened the pieces OF glass are
occupy In the lens. They are then ali ground
at the same time. Ike single piece.
tive OF telescope consists really Of two lenses
one In front OF the other. The outer one Is
inner one is csacave:eonveI and md is made Of
crown glass; They ht together like q single
sSonK. psSe M uasnman sns nhangtSetures h his con.
double convex lens but separately. OF course.
In ono OF his lenses eacn section. though look.
ing like single piece has an outer and an
inner layer.
The advantages OF Mr.. Gathman's invention
are wonderful and inealculabls. The hIst is
that all limitation on the Size and power OF tel
escopes is completely done away with. The
manufacture OF the ierkss forty inch oblcc-
tive Is regarded as daring feat and wonder
plus ultra OF astronomical exploration. The
main reason is that the larger n lens is made
the more uificult It becomes to exclude air
bubbles. But there are al so other difficulties
attending large lenses. They are greatly af-
fected by expansion and contraction and when
set up on edge long time they are found to
sag. or mash together of their own weight. SO
as To interfere with their correctness. Now "A
lens made in sections has none of these in
nrmities. and it is altogether possible To make
It 100 feet or 100 yards In diameter il desired.