New-York tribune., 1879-09-02
SECTION A. MATHEMATICS.

of the worlds neurology as bearing on
The progress of science" President Bar
nard had before him outline of his essay, but he
departed from this at nearly every page to make
minute and interesting descriptions OF the instru-
ments and methods TO which he had OCCASION 10
refer and 10 render popular the more technical
phrasology by simple illustrations. Following is
an abstract OF President Barnaru's paper:
The first committee appointed BY this association ior
scicntnc pnrpo.e was a Committee ON Weights Meas
ures and Ccinsge-appointeo In 1872 tue hst a..
being Professor Joseph Henry Ihe coinhilltg1e VIZ" US % r
struced 10 report standards, and on the o'
"A scientific and practical metroiosloa,, S!r, !nonp
let one. The COMMITTEE entored into WIDE
I'm So m favor of decimal system. and re-
porfcd resolutions h. 1867 In favor Of hc metric system
President Barnard member oi ths committee, hau
been led many years inquire into The diYersiiie
Of weights and measures In use among tne ma
disappeared since THE beginning 0i our own
These dversi,ies were very numerous as any Oh Tue
The dveTses exist not only where uants are uiht
nut also where similarity oi nanes lng9, ,'iI that n
such diycrslt.cs exist. but lail to snow; a. ine
limits Oh disGvp"ney' r9e9snrs nno wnich have
common name C3l The gradstons OF diherenoe-ls. Z.
whether the values are distributed pretty uniformly
through the entire range whether they are GROUPED
about certain governing values; TINS because he Ic-
nouares arranged alphaDeteally-the measures ne
10 which they belong Many places have the
foot measure, The same und mea.uIe etc Ihose
values being repeated under each geographical hme,
lie
more numerous tnan they are ihere ar MAY & &
aries but only which can make any earn 10 com
pe.eness. II is Doursthers, published III le4O ahdho"
iu order to obtain anything like an iniellicble
view of thi. complicated subject II was nee
essary 10 prepare tables in which the values
are arranged in arithmetical order from ne
the o,ineasure and the ponndweight
presented TO he Association. As 70 -" ]
and TuTse! exceptcd-Gs the cubic mas been 'ha' oI
i century ago. every province large town. orcon-
siderable village Continental Europe had IFS oN foot
measure. The number OF distinct values lncudrd IN
the cable il 2s2 six OF these are ancient -7G modern,
and in a century ago e66 have been su erscde by
the meter, and are practically abolshe@ -. ,,.
The table OF pound TcightS--ihls Wclglt haNlng
been also IN c use M GSyr Ssye Sre .nperedcd by
tne hosTam An examination OF these tables i'""s To
Ffrst-Ine successive differences are all small No
large gaps occur any mere The values GO not cluster
around any particular leading values
Second-The range II sDguiarly large For the iooi
II extends between Inches nnd - Inches Tor the
pound. between $50 grams aud loo grams
Thir-1 place has often several values Or the
weight measure Oi the same name-sometGes widely
Io,rA-Dstant places have values very nearly
thousn not quite sike nut oi obviously IiLi
or ''' occurs eqaeniy group Of ss
woights. decidtdy but only sghtiy unorihS, S'hg
evidence Oi a common origin.
The existence of such groups demonstrates the alb
sence in past centuries. OF anything like propcr'gov
ernmenal control inspection Of standards, and Of
any ihing like precision IA copying or Duplicating stand
ards. Nhen there multiple " ghts or measures
under the name ia gwen place. some one Is Used
for gOnera purposes and INC Others for special Thus
we have often besides the "u-nal" fooi-measule.
the carpenters foot the bu des 4oot the quarry foot
from three to seven GiGerent pcund-wechts. Every
place has as many ~ two v have TWO ourselves thc
res pound need not eount sHce is eanai 10 the troy
pound, though differently diS ced soeEeon IA sweGe.
mas seven pounGwclghts FIrnAiOri-ou Nlair has SIX;
mauy other scos five and for ~d three. Eight years
ago. member OF Parliament nr, Oaie We n"o, sta,ea ~
ierent poundweigh,s used for difercn, articles but
even for The article ON different market days
rLFMENr on UNCERTAINTY.
The obvious inference from all THIS IL, that largo
element OF rtnty must have entered into all meas
ures made during the prevalence OF these conditions.
The influence OF such state OF things upon the progress
OF science enough For all exact sciencethe
pure mathematics apart-s series Of determinations Of
ouaniity The kinds OF quantity 20 be measured are
length, surface volume direction tauguar). weight.
lime, number. temperature, density energy pressure.
Neurology In the widest sense. IS the determination
o; quantity OF Whatever KIND by iDsttrmenta means
ought TO be characterized uy
| /. Identify Qor different servicesl.
2 IDVariab li.y tiOr different timesl
when standards not ideuueal there must be some
determination at equivalents. TIL the present century
tbesc conditions have not been fulfilled
The slow progress OF science among the anciens was
genius or Of intellectual activity. The Greeks
were profound in speculative pnilcscpny' ana accom- econ
uans were adDanced IN ma,1s,SaiieaI5 ny,; INV -
tsaon The RomSns %s,e eehsnSnea, S CSu NIL
never highly hourishing taan 1000 yoars ago In
!
ences. Astronomy existed IN name. but made no I'D
Vhnces.
studied by the Chadrans upon their mountain tops II
was the fonndsiion Of vory elaborate aud Implicated
stationary. nearly SO, for twenty centuries.
1t made no progress because II had no Instruments
adequate the determinatou OF rhe exact positions of
celestial Objects or the exact time OF occurrence OF
nxed Instruments the pendulum clock tho telescope
Instead Of these II had only the asroabe and the sand
Records of ancient eclipses are worth nothing now
except for the day Of occurrence. The hour not
noIed siil less the minute OF second
The first great stride IN astronomy effected in tie
sixteenth century by improved Recommendations Tycho
Brane, With liked observatory, iarge circles ana
clock. made determinations OF planetary positions
nearly enough exact 10 form basis for just theory o
the solar systen Though he used only plain sights. Ike
those OF surveyo compass, ana Trough bi- meruin
ne as ascetalhed 10y recent reeAninlna,oh M was M ~
error by quarter OF degree yer through te c3nse
qucnt unavoidable errors OF nus oDseryatlOns mere
clunmercd to tine eye Of Keper the truths with which
his name VIII be forever associated, as the laws OF
planetary motion.
I'm spite of the imper'ccion OF the data which reveal
them But the inStrumental determinations which al
termnedi would have afforded not the slight ground 10
,nspee the sSsense or ,nen as S9erTn ,
sortes axis They dia not not serys 70 a9sh even
that the transit OF Venus visible in Europe N the
seventeenth century occurred without been pre-
diced. aud observed by only single Individual OF
the human race Isaac Newton's discovery or the
causes OF color IN thin plates and consequently OF the
periodically aitern ane disposition OF light to reflection
snd transmission, which was Substantially demonstra-
ton OF the truth OF the unduatOry theory,
though lot recognized to do so at the time,
was one which did require very high state OF
fection In neurology to discover. The inch which
Newton employed as a measure WAS not qlantty de
termined with extreme precision IN NewiOn's une.
Hence though the fact of the alienation ftuy
tabshed tile loGsth Of the intervals Will not very Sc
verey nFra with the Results OF more recent deter
limitations by fIacnbofer or Angstrom.
New:ons history presents remarkable Instance IN
which imperfect measurements seriously retarded "A
discoverytHe greatest in fact o. his nfe
This the truth that the which mataiDed the
planets In their orbits is the same which causes
heavy body 10 fall Oh the earth. He had reached this
grand generalization H. his mind. II remained