The sun. [volume] (New York [N.Y.]) 1833-1916, 1877-04-22
THE ELECTROSCOPE.
Light Wanted On the Alleged --latest iarve
of Scientific Dfscoxcry.

To TIE EDITOR OF THE SuN-Sr Prof
J. w. s. Arnold. NJ. d.. of the University Of IN,
City Of New York has been invited Ivy Chnn'cl.
lur Howard Crosby and other prominent eli.
zcns Ia give 70 popular illustrated lOo lure ON it
subject ~ Light and VISION" in Chickcrns
Hall. on the 2i'h " In lis month. DR.. Arnold is
AN ahle cNpounlrr of scientific facts and thco.
RIGS to uns'cntin' people but. like most lie turcn
I'M mt on porularizng the suhie.t of their Il y
course. ia in danger of amus'n without m.
struring. This danger is specially great VIII I
lerturing on light and vision. Tn, subirt nat
urally suggests tho usc of dal1 NJ Illustrations
and the audience finally dispense without rocol.
Letting Of the lecture anything but tho fact Of
having been prased and startled with cxhihi.
tions " the beautiful and aston Shin r,sull
obtained by skilfully controlling the Joint work.
ing Of various laws and forces Of nature II DR.
Arnold should be willing to dispense with the
customary displays Of magic lanterns and rain.
bow r1ects. he might introduce an experiment
IN which. no doubt many OF his hearers art
THIS experiment would not be much out Of
his way As he will have to dwell upon tho ma.
ture OF electric light he VIII probably have
thought also Of dclightng his audirn - with an
exhibition of the apparatus by means Of which
acurrrnt oi ELECTRICITY a converted into u pow.
in TINS experiment to a New York auIicn @, who
see enough Of el,rtric hight in and outside Of
Il.
inycrt the PROFESS, and convert n stream Of
light INTO u current Of electricity accord ny to
tho laws of the correlHtion Of forces. he would
be sure to please hs audience with something
new. startling. and Instructive. This expert.
ment would be Oi practical value also TO many
rHp talists.
The do trine of the convert .bility and recon.
vrrtlbIllty of light and electricity Is said to have
sugg' strd to u New York 'irnt Il che idea Of
constructing a wonderful apparatus. 10y means
OF wntch ObJerts or parsons removed thousands
Of miles may be- rendered visible. TINS co trie
telescope. for which TIA" familiar name II clec-
tros'Ope has been chosn n. W luld be- II really
practical, "A valuable adjunct to the telegraph
system, as the waves oi light can be- carried
through the ord nary wires and ahlrs. II fen-
sible there Ia no doubt that there ara millions m
H. but as long rs It's Feasibility has to be- re-
gnrdrd ms an lfnpaus bile hypothesis Il Will he
better for our Nor 'hHnis to Keep their mill ons
out Of II. DR.. Arnold might give them some
practical advice IN regard to II. Yet II has ~ DO
needed that DR.. ArnOld's inability ~ repeat
the experiment OF converting light into cleo
trlcity, or the nrredulriy Of the whole 'irntino
world that IL can he done. does not really Il r.
prove anything. Ia the CONVERSION Of n current
of electricity into sir'am ~ light IL is neHcs-
sary to use some mineral substance as "a mo-
dunn. and il is nlghly probable that the medium
10 be employed in tur conversion of light into
electricity Is secret which the originator " the
idea of the electrOs'op is not ready 10 dvuige
Nevertheless. : scientists should not tccl afraid
y give thenr honest opinion on the subject.
Many great mon have before pronounced "a fail
ure an invention which at'rward proved
great su cess. and DR.. Arnold should not hest
his coming lecture. An ELECTRICIAN.
NEW YORK Aurtl 81