Juniata sentinel and Republican. [volume] (Mifflintown, Juniata County, Pa.) 1873-1955, 1876-03-08

Plaster Casts.-Twooonaf1ersble pri-
ga Arc offered By tho PsuGl6an govern
meut for TIE diocoveEys tpnpectivelys
Of 4 new method of cLea1SinR plaster
casts. statues, ETC., and for The inven-
tion of new Ensserial possessing the
advantages of plAstef, bet which will
not deteriorate BY repoated wnshinRs.
The conditions Of the first prize are.
that the method must Be applicable, in
equal deeroe, TO ell kinds of plaster
occurring In trade. and must not di-
minish the hardness OF the cast. and.
in order to entirely preserve the deli
cacv of the form, those materials ara
excluded which do not coax into plae-
ter it IA not necessary that tho Of1n-
nal color of the platter Be preeerved-a
yellOwish or any warmer tint will an
sWer-but the evepnesk OF the cUlOr n
Indispensable. Tho casts must also
stand repeated washing with soap and
lukewarm water.
The conditions of the secoud prize
are, that the new material costly allow
casting in original m0ulds without
their becoming moro injured than with
platter, and that it reproduee the mould
rs exsctly - plaster: that, - In the
above, the material need not have the
color Of plsst~r,-s yellowirh or anv
warmer tint will anewer the purpose.
but an even color IL Indispensable ;
that the sOlidity Of the material he not
less than that Of plaster. 50 that Il may
lie uss for the largest casts; and that
the ca~ts made of the material 10 able
tn st.nd r, mated WashiuRs with SOAP
and lukewarm water.
AyronocmeRf for St0YtinH Cnrs.-A
recent plan for starting cars appears "a
pO.sess some advantages over any Of
the coptrivsnces st pi esent in use for
this nae. This plsn conrists in having
a smali gear wheel rixidly attached to
the inner aide of ono of the wheeIs-s
large internally -t0Othed gear wheel
b,.ipe aIao attached to the inner side Of
the 9th. wheel. A shaft. placed para
parts, Connected with each other BY
universal joints. and, 10 the middle
part of this shaft il attached one end of
the spring. which L. cOiled around the
shaft. The end parts Of the joined
shaft engage by gears with the gear
wheels named, and devices are provi-
ded for locking the levers, which bold
the gear wheels In gear aud out OF
gear.
Now, when the car il to be stopped,
the apparatus is so regulated that the
forward movement or momentum OF
the car may wind up . spring: When.
on the contrary, the car is TO be star
ted, the power of the spring may be
applied to the wheel near its rim, and
thus, with Q great advantage of lover
age, assist in starting the car. In the
same way, a. will be easily understood.
the spring may be c0iled by tho ad-
vance of the car when upon level OF
down grade, and held, to be applied TO
the car when upon . short upward
grade. to assist in its propulsion. This
plan, il is asserted. accOmplishes the
object in view in o manner the least
liable to objection of any of the arrange
ments yet proposed.
A., ;mnro,.d N.fkod of Etch,no Con-
~.J vyssy-Ir ovoriook;n~ The re-
csnt na,dho"k. ancvcioned;ss tech.
nnI; o;c.I d,c,;or.r;as and iournaIa
n"anv d;recs;ons for etchiny metsls'
asnsc;ailv STEEL and conner. are fOund'
r. 70 q n;fv however nat mosf of these
nrascrint;nns univ verv imnerfectIy
tulf;l the nnrnose INTENDED. While sOme
of them are even utferlv impracticable,
"o mGor".nr as,'.c;"iIv tLe Hat.IInroi- +
cal N,.anw ~ Nnremhero1 have mn
SertaEan the task of snhmitfine the
nrocessas r - nronosad nv the hooEs IN
pproct;csi ,Ssts in ordsr 70 shoi;sb ma.
~ oe thau, wh;ch I;te q chron;c n.
sS.sa sra c.rr;ad }rom cenersf;on r.
~ansr.t;"n hv h..;nS con,ed in coc.d
f.;tb IN ths hs,Shonks and encvcione-
d;.s and r. ;s e1necfed that oniy very
sa% &c ,han, w;i1 stand th;. severe Or.
Nv, aaI" VI 'non "' ''""~ ''1'' '0''o "
Pndo,rh w.,r.- aa;tor of IN. San
,n'.I Chpn,;"ai T.1h"oi~a;r.I Ponortn
$1,000 IL. Cic.,;scSsr Tscl nolno;ej
,sa..,o,s ~ rsc..r, C"rr,.n ;nSnsfr;ej
;nnr,.I ,hat ha t,,nn6 th.t soirf;ors o1
hron;na yo, nH, 'c md hrou,;ne - comncnnds Were
most most axcsIient % lie Tor the etcbine 6f steei.
H. nses mart of bromine fo loo of va.
tar and in csse he wished tn avoid the
vanor ~ th;s volstile material which
r,sv ;n;nrs daI;cata ob;rcts around. he
nrefsrs a solnt;On of / mart Of bromide
of mercury in 30 parts of water. For
intion cf bromine in bydrochloric acid.
as nrafershIs above ali other seents
Inawn
Noisfure ,n the Air and Intens,fp OF
FricfmnaI ELaxficifv.-Certain tbeOruti-
caI cons;derationn having led ROssetti
tn the conciusiOn that OHM Law should
annIy Tn frictional ss we'll As to eslvs-
mic elec,ricity. he has instituted expe-
rimeuts showing that. under similsr
Conditions and in the same series of
eIperiments. the intensity of the cur
rent il nearly pronortionai 70 the yelo-
civ of the Rotation Of the disL of a
Holt Machine. This relation in in
fiuenced by the moisture of the air in
such a way that the humber of turus
which the disk must make. in order 10
xiy. rise to q stre.m Of q certain in
iensity. in greater in a moist than in =
dry atmo.piere. The quantity of work
Which must bt. exp<uded for the deyvl-
opmrnt of elect icity is exactly pro-
,ent: therefore. the ratiU between the
work exnrptied and the r,.suIfins inten-
sity If th.. cnrrrut IL the anne With in
crsasiux moisture.