Daily Richmond Whig. [volume] (Richmond, Va.) 1865-1869, 1865-06-14
THE SCIENTIFIC TESTS.


Il seems impossible that there can be any fault
in the Atlantic cable when the Great Eastern goes
10 sea. 10 say nothing Of the tests applied TO it
at the manufactOry il Is tested not alone after 1t
has been taken on board, but du ing its delivery
into the ship. As soon as length is brought
alongside, one end Is connected with the coils
already on board, and the ether end with the 10.
struments IN the testing room. The circuit IL
thus made through the whole extent Of the coil
the pOlt ton on board and &c portion alongside
The process OF hallng in then commences, and
the insulation Is continuously observed. The in.
slruments in the testing lOom record the smallest
deviation from absolutely perfect insulation. 1t
will be understood that an insulation which shall
be quite psrfe5t as an electrician understands the
word, is not aitainable. piece Of metal sepa-
rated by means OF the puIeSt glass, and enclosed
in the direst atmO,phete that con be obtained
will If charged with electricity, lose that elee.
tricity after time. In speaking OF insulation
we must therefore be understood " mean an ap'
proXimate condition; but the approximation IN
the case of the new Atlantic cable comes 80 near
to perfection that this rough tarry rope is sclen.
tihc wonder.
The last dying pulsation Of the old Atlantic
cable was forced through II by means Of O gal
vans bat cry consisting OF two hundred and forty
cells. The submarine telegraph from London 10
Amsterdam Is habituol,y worked with battery
NJ fif,y ce Is and such Q battery Is commonly
used Tor the other submarine lines of Europe
signals have been repeatedly sent through more
than thirteen hundred mics Of the cable now on
b ard the Great las era by means Of one cell.
Galysnic currents 50 ieeb that they could not
aaye been felt by the hand, and might hav, b.
passed hRrmlessly through eiIeuit compIted
by the operators tongue, can be used to convey
messages along length OF cable that would very
nearly stretch from LJndop b 81 Petersburg.
over needle insti umsnts, sacn IS those IL ordi.
nary use Tor land 70 egaphy, q current from one
cell would 10 power eHs,
II record such FAINT pulaationI Of electricity II
Is necessary TO use Profsssor ThompSon'S mirror
ual,Auomster. 1kis beautiful instrument con
sists of mirror about The size VI f1arpepny
piece, made Of microscopes glass, aud 50 this thst
n weighs only or In. On toe bjek Of this u T.
ror a minute msgne. Is hSed and thus supple
menied II is suspended by Silkcn hbre in the
heart Of o coil Of wire 50 that any curreat pass
ing through the coil defects the magtie. and tic
mirrur along with II, ray OF llgnt reelected by
the mirror falls on seals, dis Rns about elshs
teen or twenly inches, and reveals its fa.nieSt
movements. Liderent combinations Of thele
movements represen: the dideSeni lat,es Of the
alphabet, end thus the apparently cratic wan
deFings Of ray Of ,isht ere made 10 convey IN
tehiseace. An instrument Of this kind Ia con.
SANITY used 10 test the cable, as ii ia hauled on
board; and it any fault had existed it could not
have passed without det, ction. Up 10 this time
when there are ON board the ship and alongsidA
1870 miles Of cable, no fault has been discOr.
cred.