The sun. [volume] (New York [N.Y.]) 1833-1916, 1890-07-27

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apparent confusion has kept the glassmaker
and opticians busy, with the result that tn
Hye-inch single lenees OF HuyRhens. that re
we're improved unon by the Invention Of tn,
achrOmatic lens by Dollund, upon which subse
anent mISoS ement pas been n rr maze only nv "
four-inoh ems, OF Doll9nd n 1900 dc
yeloped into. the nine.inch lens In 1880
and from 1915 to 1861 the fifteen inch tele'
scopes ut Harvard observatory and at St
Petersburg were the largest and most power
til to-day the size and power have CONSTANT,
Increased, tltst to eighteen inches, thon L
twenty-three, twenty,siX thirty thiTty.siX. apG
working upon one forty inches In diameter
At various stages of the progress Of telescope
power had been reached, but after each In
crease II was found that with proper seec;
ton Of site he density Oh the ,atm3srhere dld
The great progress in telescope making and
the consequent development OF astronomy are
due In u great measure to tho efforts, of one
house. that OF the Clarks OF Cambridge. In
Avian Clark Sr was sr making seyen and
lS6i the Clarks made be eescoTe Win I'm an
Was made ES1 By III The cIarSs in ISL dqpicate
OF yi P "s twenty a thee inch for Prince.
ton, and then ono of thirty inches for the
81. Petersburg Conservatory. Next the thirty
they have reached the forty-inch glass. Most
Of these Telescopes were ut the time the largest
en- n9sf RhS aad t HeH or
| tnch had no compeers. No other opticians Ia
the %EFd are rec to unIs.ss s me TASK
| The work OF shaping these great lenses is Of
the most delicate description. tho least de.
parture from entire. accuracy being sufficient
| the work Of fnshioninR the lenses Is done by
machinery but the most OF II Is done py hanu.
| the rubbing of the thumb covered with rouge
| over tho surface. In fact, after the lens, has
| hardest work comes. In all the arts there are
those who. have kill and those who have
genius The ska ar, s tES go tS
| the glasses, and II these calculations we're cor
| rect the lens would be good, Tho Renius.
fashions 1t out with hut the incidental use Of
measurements, depending upon his oye and
judgment which are more unerring than
mathematics. The Clarks belong to the order
on tn the skin Of the HoPtisI%p
be useless. There Is but one firm in the world
that can furnish such glasses a. that, of the
be SHAPED by the CIarks and that firm is Fell i
Mantois of Paris. The production OF IA disk
perfect in all respects for lens OF this size is g
Witch Wit it Is made must have the perfect rela-
ton or it will not have the necessary
SE Of desV is ats For
this reason the glass. has to be moulded and
remoulded time and time again until the
even after this the optician pay find some lit
tie inequality neeessitatinE Its return to tho
eruesie tne oroISee tSe roauiee RESULTS
The mass from which the crown disk OF the
Lick TELESCOPE was mage a %elGned d prfimhriIy
/ 500 hounds and that for the forty-inch glass
Grown aud flint lenses) considerably more
Tho objective OF a telescope consists in real
ity oil two lenses. the outer one being OF crown
glass and the inner one OF Tint Rlass. Inc
Sides and tho flint glass plano-concave or
concave on one side and plane or fiat on tho
used Is because of chromatic alterations
which occur when asingle one is used. through
them the Ta Hs %a s n, hnEE Sr
defect, though there were others: but 1t was
obviated by combining two kinds OF glass hav-
Ing the cbromate alterations Of the bi-convex
crown glass 1t is not a ,s,essnns the
the amount 'U%' light that rSSchSs the
only receive 70 many rays rs fall upon the
pupil. BY the use Of ateiescore as many rays
upon the object gla g. The pupil or object
glass of the eye has diameter OF about one
nth OF an inch. BY tho use of the telescope II
is virtually increased in SURFACE in the ratio Of
the square of the diameters of the objective TO
the square Of one-llith OF an inch. the diameter
Holden. one OF the astronomers of The Lick
Observatory. has committed the relative bright
ness OF star seen with the eye and with the
different si2"d telescopes. 1.-THE brightness OF
a star seen with he eye alone is !. with a 2.inch
telescope It Is 100 times as bright 4-iueh tel
esCoUe II Is 400 times. 6-lncn telescope IL Is
1GO) lG-inch telescope II Ia $500, 32-luch tel
escope il is 81, iOl times as bright.
The writer spont nm afternoon recently at the
factory Of the CJnrk Hrothers. at Cambridge.
About the 4O-lnch glass, whic b Is for the Uni
yersity of Southern California and which ar
the managers have not yet given him con-
tract 10 make the lens for 1t, but he eNnects 1t
tician In the world can do the work. SO there is
no doubt that no will 10 it. Mr. Clark has Of
feTed TO- make the s & iGr sUV
Photographic for *.OsVjo
tho importation Of the glass, When Charles
sumner WAS in the National Senate he intro |
duced bin designed especially to allow A.
lenses FREQ. and tho law still remains. But |
recently the Treasury Department made de-
Jected to duty Of As Der cont. This meant
everything TO the CIGrks. rs they. would have
had STe9dy uI the sass
being Included MIR. Clark went to Washing
ton. and. backed by, several distinguished
partment thar under the law the glass should
come IN free. but First Assistant Secretary of
inc lTeaSUTy lcHeHOT, WHO Inuuo me
decision, refused to te convinced. Mr..
Clark returned home with a thorough deter
minatiuD t. take his tools TO Europe and 10 do
his work there. but senator Hoar interested
himself In the case and the decision was re-
versed. Mr.. Clark says that no will In all
not begin on The lenses for year,
and, a II will take two years TO DO tho work on
both OF them-the Hint glass has not yet
arrived-it will be three year, before the tele-
scope will be finished. When competed. it
vii be mounted in an observatory TO be
situated on Wilson Peak, thrteen miles from
Los Angeles. Cal Mr.. Clark and Prof. Picker
ing OF Harvard think that this l. the finest site
'or telescope in tho world. The atmosphere
Il clear and steady conditions necessary Tor
good observations.
1t should be mentioned that Mr.. Alynn q.
Clark IL practical astronomer. and Is the dis
'overeT OF many stars among others tho Clark
star, within the trapezium OF Orion-with tho
Lick telescope The magnliying powers OF he
Lick lonses can bring tho moon TO within
About 100 miles OF the earth, and the 4O-inch
enses will bring II to within q much smaller
distance. Mr.. Clark has Insisted that he shall
ave tho mounting Of the new telescope. SO
hat the laundering that took place IN the In
tance Of the Lick telescope, and which neces-
tated his finally being called upon. shall not
20 repeated.
TREASURER SUATTE REIIRES.
lie Will Make N Settlement Before Long
About the Church FuudS.