New-York tribune., 1906-10-22
NEW LAW OF STRAIN.
Government Scientists Completing
Valuable Research Work.
Iron The Tribune Bureau.I


Washington, Oct A.-New facts in physics have
.sn asoertsined which wifi lead eventually TO dis
crT,ry OF the law of elasticity. according TO
II announcement OF extraordinary scientific inter
H uaas by government experts. They have been
eo,incrng tests OF q remarkable character with
srss znd steel tapes stretched IN the interior OF
sas Washington Monument, from the top to the
base O. the structure. a clear but protected drop
b E fest unobtainable elsewhere.
IA tie result OF the investigation IN testing the
Elasticity of the wires, which IS the most elabo-
i.is Of its kind ever undertaken. the American
basatists. who are Of reputation as chemical
nd physical research experts in the United States
Geological Survey. now believe they have obtained
kasanite formula which VIII be OF immense value to
Is engineering world Little mas peen EnoWh
lbout the nature Of the experiments conducted IN
sy he officials who had them in charge and few
ssre aware even that wires were hung IN the
rGty were being carefully observed from day to
Fay The tests were begun two years ago, with
ljoEed for -o H. irS ane 81 the experfments viii
s1Te Ia Msrc8 .S bat Ihe q government experts ind
lHt 81 the calculations necessary cannot pc m
Easd By that time, and an extension or time for
neither wear has been granted
The observations thus far. according TO state
a.nt scientist IN e charge have already demon
EEated beyond ali question that no theory. OF OF
l be maintained This applies particularly to the
eny better theory has for more than cehLIiry i
ssn regarded as cardinal principle OF PHYSICS i
ehaIlos and engineering practice, nancy tnas
re stress q q body IS proportional 10 ltS
strain" Dr.. Becker says that such g theory Is
saisn2ole when applied 70 problems OF elasticity
The Eooke law Which was first stated in 1873 by
E.1trt Hooke, an English naihenaticlan M sno q
t@scst ne says, Is proved applicable TO such tts
lazcipIe Data Go coilected from the wire observa-
fors IN the monument confirm all doubts there may
Eesh!ngton scientists believe that they will fur
tsh figures which Will give the world the true
~ governing the stress and strain OF podies, Us
soas relating 70 the properties Of matter. TO the
'0uf exDerinents In the washington Monu-
EEsaL SAID Dg. Becker to-day, nave peer sro gon,
fhort distance Of the floor. The obellsk was
.sss Of its feat geigRs Go and stabify and other
ssvs.iages as place for carefgl seeming 2p fba
Il mine v,fcS woI,ld rT ~ course. have made the
sork nore dtFicJlIt For the purposes OF the test
rres ana rfeeI ;apes TIC longest possible stretch
. wire is desired 20 enable the experiments 70 be
,~s-1octed with the greatest possible accuIdcss
ss elongat,cn In the monument We are enabled
= ooserte an extension Of the hundrecth pa.l -
~ lpllnetre or z proportion OF ! 70 1osoo!,Ve. ss
e.ssn observation IS made with cathetoneJers.
s.bratec weights attached 10 the wires for perlods
,se are used 70 stretch them for the putposes
..snoed. Careful observations are made each day,
- FACTORS q electrical conducuvity and tenn
tTeseost't haFlng 10 De reckoned Win. OF OSr
@s.ecsIon the wires are. moreover. encaseA IN
,
ESQ in eizs and formation. one Of them being
- nhcsr constant weight thermometer. care
Exercised not TO exceed the elastic limit pf the
t.ts with weights, the law changes when the
r. applied IN stretching the wire exceeds the
80 ot restitution 20 such extent that the wiro
cs--IIafeurly stretched"
s.arlrlenting upon the Importance Of discovering
-L-e law q elasticity IN case The goYernIneIlS
sctlls's are successful. DR. Becker said he DC
=. Eare u make TOO roseate a predlctlon epqul
E.nee "e -
TIE whole science Of elasticity" said he, sis
c.s.e 70 - 50 complex that IL is Impossible 10
" s-ss any but the simplest cases For example
srs anEble 70 discuss the stress or the interIla!
sSn q g bar supported at either end The
ts-eEs tat stress IS proportional 70 strain IS only
s.-Se.e Tor extremely small strains II practically
--~--.ss.o 70 this: That very minute porGor OF
fss g lJne cetncGes with straight line. In puild-
a "a a. he cutter surface. For lack or knoWlsoge
boss1 y rle Internal strain they are unable 70 ds
- - pressure IN ideal manner, or proporLop
IL s1at i is equally strained. AS an example OF
fs-e 1lorss Of engineers to meet conditions wnicn
rsl.sh shs;cE exist but as 10 the exact reletion OK
a. - laey have no accurate scientiho knowlecso
Ia ns@pe adopted for railroad ralL5 may De cltea.
4 gSg.sS!,2r form being designed 10 meet chhnges
tf y. II IS ordinarily assumed IN pFoDIoiLs
b. .s@cy that stress Is proportional 70 etTsiitl.
q s.. sppneo 70 changes IN volume as the result
yerrsrcE pressure This subject IS ot Efe4L az IT.
y. several ways Discussion OF the peLLs.ty
Z. Is ssrth Is quite Impossible without know,iAg
r1ulS 80 oI elasticity Discovery or the uaS -
In result IN immense simpiihcaion OF engJnsss.
izsf g.sfes Z would Lead 70 simpler eqaauoIs oy
sFr.Jg ss:yEliee. When the InatheIlatlcel law 49,
- p.tncipse OF physics is known tnS ttte
[a&d cosH.cients and psir relation WIZ Do