New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1880-11-20
SESSION or rms LAST DAY.

of deaths of members of the Academy closed
the session and the fall meeting
SESSION or THE LAST DAY
The session was opened by Professor Henry Draper
with a paper "On Photoaraphing the Ncbula IN
Orion" After distributing copies of photographs
obtained b. him, Professor Draper said
re gaseous nebu@ are boi'cs Of interest because
they may lie regarded representing an early stage N
tie genesis OF stellar or solar s,tt'ms Matter appears
10 exist III them IN simple .oin, a. Indicated oy t5r
therefore, 10 ascertain what changes occur IN ihe
neou a, ano detimue I"e~.oe, lne law rrgH'%tuE
made Of souc oi the n"huF' ana especially @, me
nrbua IL ORION. Tor upwards oi 200 Fcart
il1t fancy Hs iaay ,,o ai-l r' 70 iaS .. PIE,
5erf Enc nS and cdh h11i o S S d one man
with that Of anolrr f. apply ihOi'SI'p,f u o'.,
ing lle d.ocu because these bodies &Ie very
FAINT and, OF ,Ou-sr. OwDg TO the carits MOTION ana
other uses they see IN not To b- al rest lh'g f.4uie
crlycn by r6ci or with tne -tca.cst precision. All
sucu dlilcuLcs lho>r arsu- lgoG r. r.cN'H NNre
of the Telescope lube mp oi zoos 'arhs' aMo'p-cG
tremOr. Wind iircu lrtes o. coCN-Woih, loSt} vi yer
etalhic eAfS-Dte uecUd 7s o! '' ',,' i,t ia LIS
Sum the p-otCrrdlh when as *nnlcc''i 10 "h'S'
fnc means have used to ootaiu The picture pre-
ia to nc Aciden. are ds oiioN-; ttipe :'h,o-
Cit'c s3n. are ,rdus TO tie plan ~ Mr. rutherford
fot cor.cr,Ir the rWs especially IJ, pAotoEftr4A; rms
telescope mounted on az ,ouaioual s'Hnd ana driven
b. q cock that made myself 4 p.oiogf pnic p.a'es
sensitive IS e. wet colodon formally employed
picture itself It viii ht obs rived I'D Tie comes
b.iorc you ,, the nelua very dstiuetin lis bright
portions. TIE sa,s Of the ir'eL lm aug som. "tl,ts
ar - greatly over exposed l".t under tAe NIX
power employed they assume q !tr-C sI', Pit} nom
To9,o.e ina much NOR OF the nebua will be- Obtained
in pictures taken N the clear Wn.er weather. Jhio
incre fog in the air; but nevertheless, the
oriclual shows traces OF the GU n sreantrs scen ~
The drawings OtYer observer. \ series Of photo
n G~rcnr Vcrs Viii Tc Il, the means Of determining
W spl O. s.
piece III tails body.
CoNp' NSERs OF HIGH POTENTIAL.
Professor George L. Barker presented to the
Academy paper on "Condensers of High Po-
tcntial'
4 condenser, he said, was an apparatus for in
creaslu, electrical quantity without increasing cleo
trical potential. The bottle Of electrified water of
Cuneas afterwards the Leyden jar, was developed
into the electrical pane of Franklin consisting of
sheet of glass coated each side with tin foil,
its simplest form. In late years conden>ers had
been used 10 eQul!Ize currents. The speaker con
tiuued as follows:
wacn cabc teIegrapy was 7eloped, The static
charge found TO occasion serious INCONVENIENCE ~
working For tAe rurp OF measuring this condenscrs
OF known capacity were Manufactured. Two point, are
import IN the cDnst, ucuOn OF c'ndeuscrs: !.
Their insulating power, wnioh Is mVersciy as their
eecro-siaiic iplcy. This anroXim tely shown oy
ressat &c to perlorauon measured Ivy the difference OF
pc.enua required To penetrate tue Insulation OBITUARY
cOnde which consist Of sheets OF parailned paper
alternating
these conditions perfectly. Hence standard condcnscTs
are made wiIp mica instead of paper In measuring the
Insulation Resistance OF an underground caole about
year 60. mica condenser made by Eliot Brothers, OF
Lond H. usrd by me; me condenser was perforated
b. Il potent u Of less than 200 volts. Corr
vots wa. ncvor ms i on c"nsIt r. in EnganJ TGafro.
tona procured current through three and one hall
miles II inc cable insulation On Thomson ly Lomeier
electro motive fOIce) gave detection OF cnB 80 scale
ad h C exdepoHny s I'm nsGiane aer
the cable. THIS WIS found 10 stand the electro motive
force o; the 900 cells without difficulty TINS insua
ing material. essentially "A mixture of beeswaX and
rOsin ore. the first requirement low specific
aducrate TIE bceswax. prevented high insulation this
was Obtained Only by ui,ng pure heeSN'N. ,.o
OF induction coil giving ten TO fifteen inch spark |
Draper suggested trial OF Of tho above condensers
upon this circuit ms Jrurtrd accordingly bv
feet of tin plate insulated by sheets % blong p per
soaked IN tho cable compostQ9 on trial IT !
was found to WIKI admirably. Using The |
Alternating current Of Gramme machine |
Oh from condenser a noise resembling
tn fusiladc OF nuskery The potential here must be
condenser SHOWS tue Insulation TO possess the second re-
There is no doubt that this form of condenser will re-
place entirely the Lvdengar for charges OF nigh poten
has me d@taed aavana s'' that H" in ""1 case
OF rs perioratO1 1t may be repaired by warming |
tie composition The perforations are fl led up by the
scInfnecd The production OF such "A condenser
seems 10 furnish new and ready method Tor detcrmn-
ing the eeetro-nouye force o. magnetic macnlucs-a
method more CONVENIENT than most Of the methods now
u use.
TILPrICITY OF THE EARTH.
Professor Langley read paper by c. ). Pierce on
the ellipuclty Of the earth dcduced from pandl-
lum experiments, This paper presented by request
Of the Superintendent Of the Coast Survey, con-
tanned a mathematical discussion of the effects of
variations in the attraction Of the EARTH which
have been recently found by the Indian survey
and by Others to cause effect similar in kind |
10 that which would be due to
q diminished density Of the earth's
crust beneath the stations. These facts are dis
cussed by &. :. Pierce, 10 when the survey has IN
trusted the Diff ult task VI determining from PEN
duium experiments the value of the constant OF
gravity, and the s,quent variations IN the form
OF the terrestrial eillp>Old HE paper shows that |
the received formula for determining the attraction
OF the earth beneath pendulum stations must re- |
ceive important notifications. The following Is an
extract about island stations:
On The wbO,e then roughly take the excres Of
gravity the island % what ii would be II the ISLAND
was built up Of extra matter, having the density 81
WAFER ana theu when take INTO account the atrac-
ton OF the ocean Itself we may say that the excessive
gravity ISLAND VIII De about equal to what WOuld
BE- pr6duced by ocean, hayIag the general deptn Of
rely The and
over the space occupied by the isand
The paper Is illustrated by typical outlines
sketches Of the oceans contour through the islands
OF Fernando NOromha and ST. PauPs Island and
also by various tables comparing the resdua!s
found by MIR. Pierce with those OF General SABINE.
Tue conclusion gave the elhpticIty OF the earth
about 1893.
The paper was discussed by Professor Peters who
spoke OF the value OF pendulum experiments but
doubted he exDrdiency OF changing BcssePs value
OF the elhpticIty. Professor Agassz spoke Of ITS
beariI Oh geological theories and Professor Lang
ley quoted some recent remarks made in the French
Academy of Sciences upon the Importance Of tins
part OF the work of the United States Coast Survey
Professor Langley also spoke OF the success with
which these dIfiicult and de icate Investigations had
been managed by Mr. PIerc., TO whom they had
Seen entrusted.
ANIMAL LIFE IL DEEP WATER
Professor Agassiz described the gravitating trap,
devised by Leuteu ant- Commander Sgsbee, to as
Gel tam the depth to which the animal fauna of the
ocean descend. The speaker had always doubted
the existence Of animal life at depths and was