The sun. [volume] (New York [N.Y.]) 1833-1916, 1891-08-31
NEWS FROM LICK OBSERVATORY
Measuring Japitrr'a notwithstanding
with N en- In the Moon.

SAx JOSH. Aug 23.-Tho astronomers on Mt.
Hamilton are liking up some apparatus 10 Try
something new Just learned by them from Dr.
A. A. Nicholson OF Clark University, who TO.
Gently passed several days nj tue Lick Obser-
yatory. Dr. Nicholson has devised n method
OF measuring tho diameter OF q star that gives
moro accurate r, suits than lave boon possible
heretofore and no came to California to Try
his experiments because he expected to find
better at mo phoric conditions at Mt. Hamilton
than ho had b.en able to got at any other oh.
servatory. lie was not disappointed. Indeed
he found tho conditions so excellent that he
selected the satellites OF Jupiter rs subjects oil
his experiments
Seen through tho telescope, Jupiter's m oons
appear to be triEht dots surrounded by faint
circles OF light called Interference fringes,
and the edges are SO vague that the measure
ments heretofore attempted have been very
unsatistact ry. varying as much as twenty rel
cent. on two successive nights. DR.. Nicholson
covered the object glass OF a il\e.inch telescope
with in ',,oque pla'e, In which we're two mar
row movable sits. operated by delicate sys-
tenn OF Sorrows. Setting tho slits close ,ogethcr
one OF Juplters moons. and then slowly move,l
the slits anart until the intsrlershce irinEss
tween the slts was then ascertalned by mi.
crume'e scale, and the angle subtenued oy
nses Of hs s saes s"m The eyo Of The o.
server being known md the angle ascertainei.
i was simnle mathematical proposition u
IF -Four mi nights in sue, e.sion the four moons Of
Jnpiter wore measured. and the greatest ynrl.
means thai the msasuremrnts aereol Within
about fi;iy miles. Dy the old method the re-
varied s"% 5S ,9 no s1y Tn
satellites by tho old method were los second a.
81 seconds. I;A seconds. and ~ seconds.
i nr; ni 81 averages were ic4' 'c' i4O
All the astronomers on tho mountain are
en- Lusiss oyer the success Of tps , enpe RI
shsi, BE- co They are parsieu aTiy
mo on:sa ea" u Dr. melhod IRE;
ylous experiments at harvnrl havlnG failed
because Of the mIsteadnssss o. the ntmosphSTs1
then some OF the asteroids. visible only
through tho most powerful telescopes Will be
Dr. Nicholson hns applied similar methods
nat MAJ liz
has found That certain lines heretofore 10.
Garddd rs simple are renlly, compound bands
dnetions Of sprciroscory Will have 70 be m obi.
fled. DIR, NJ ,che'son is molestIy reticent about
1n 'o Of It,
The Mt Hamilton men are No. tho least bi,
enthusiastic over the heluest lOO.0uo trance
to any ons who shall discover means OF com.
llaRei; Director Holden was per uad-;h win
difficulty 10 discuss tho prorosition. he re-.
earaed !. as absurd and n.ima,ed Tint il Was
The mos; interesting Tuesiioh that can be
asked OF astronomy" said Prof. Holden. ,is
itei butt is uu.s ion that cannot lie an.
t ones pi"nes a1o p &c @
there is a wide difference between tho.e
.%s ESsfstsns,h tho sendons abe
That lie a Gould Se there Shsther the plsns!
and cold pre-. ali uron its surface: but there 4
will be ahle to discern the sexual nresenre Of
bower Of Telescopes We can make in q
iew hours nm eye.piece OF enormously grea er
e.c"pe but that would simply increase, The
| effect 81 atmosphere disturbance and make 1,
impossible t"ses any VI T., ,h,.,r;n, nuo,
aairs only i eomrs a'ivsIy small sum to pa,
most unlimited size. obs dian 4 simny blaes
and REQ from defects tnan q glass that can b
have a small boulder cut and polished . test
the quality. and II that should prove satis'ac-
tory would have a reflector made from bis
boulder. say fifteen feet in diameter. silver the
| A reflector Of that size would te about twenty.
| five times NOR. powerful than the Lick t-ls.
scope. and with /, 8 aid the surface OF the moon
for eInmrle. could be studied very minutely.'
:, Prof. Holden was asked what he thought o.
Edison's scheme OF putting a coil OF wiz.
| making q teleph ono to transmit sounds from
| the sun. Prof. Holden smiled as no replied
| line. Mr.. Edison has corrrsponded with n
about his project. and We have suggested thai
| the induction in his big elactro- magnet ma!
interfere with his purpose. He will be NOR,
likely 10 hear things that nre going on In tlt
earth than TO- catch sounds from the sun. !
! seems to mo that he might As we'll tut his col
around the sarth. don't think he will get an,
| telephone messages from tho canal builder
| n Mars and 10 no. think il worth Will. To-
| astronomers to pass any o! their time t!yinl
| to ascertain II other planets are inhabited"