New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1881-07-20
RECOVERY CONSIDERED CERTAIN.

Us q mistake IN nursing. Inc fact thaJ thc leNer
disappeared last night and has not returned to-day
confirms this view. The wound has discharged
more to day than at any previous time, and the dis
charge of healthy matter. The physicians are
particularly we'll pleased that account and every
day strengthens them in their conviction that the
Ori ginal diagnosis was correct and increases the
intensity of their against those outside doc
tors who have claimed to know all about the wound
without ever having seen it,
As the President gains in strength he talks at
much greater length about affairs and learns more
with regard to subjects of current interest Mrs.
Garfield now spends the greater portion of the day
with him and reads to him n good deal from tho
newspapers. lie Is pleased TO hear OF the world $
dvngs and is anxious to be able personally to
examine the newspapers, particularly those of the
There Is no longer any serious talk of removing
him. The physicians say that he can be made as
comfortable in his bed chamber as he at any
place in this latitude. The rcfTigeratng apparatus
iDSures comfortable temperature.
TIE SEARCH FOR THE BULLET
.STEETsTING PRELIMINARY EXPERIMENTS BY PRO
FEssoRs BELL AND TAINrOR WITH TIE HUGHES
INDUCrIVE BALANCE-DIFFICULTIE To BE
OVERCOME.
IRY TELEGRAPH TO THE TRIBUNEl
WASHINGTON, July 19.-Sevcral gentlemen called
LAST evening at the laboratory of Professor Bell to
witness the experiments which are mixing ly that
gentleman and Professor Taintor with the Hughes
the detection of leaden bullets in the human body
Both Professor Bell and Professor Taintor were
present and explained tho principles of the nstru-
ments they using and illustrating their progress
by experiments.
The original Hughes balance sent on for use con-
sists Of TWO argand lamp climneys each surrounded
by two coils of insulated wire wound upon wooden
spools. The chimueys pass through the centre Of
the spools, which fit them closely hut still
loosely enough to be movable for pur-
poses of adjustment. 4 clock placed in
an adjoining room, that its ticking cannot be
heard by the unaidcd ear, but connected by wires
with the operating room, is arranged that with
each turn of the baauce-whccl, a small wire is
dipped i'm n cup Of mercury and again drawn out ::
this movement completing and again breaking the
primary electrical circuit, which comprises one spool
upon each chimney, a battery of several elements
and the clock itself
A secondary circuit is now established embracing
the remaining spool UPON each chimney and a com
mon hand telephone. but no battery. All being in
readiness the clock is wound and set in mo ION and
the pulsations of electricity pass the primary
circuit and through the coils of wire which form
a part of it. The proximity of the coils OF the
secondary circuit creates by induction correspond
ing pulsations in that circuit, So that the cf-
feet may he heard by placing the telephone
to the ear. Now. if the two coils of
the secondary circuit be so placed that the con
voutions Of wire in the same direction
that Is from left to right the rcVcrse-the volume
of sound to be obtained from tie telephone will be
twice great as could be obtained from n single
coil of the same dimensions; but by reversing one
of the coils of the secondary circuit the inductiye
current created ia either coil exactly ncutralizcs
that of the other, provided the adjustment be such
that they are Of equal magnetic strength. TO make
them equal, or in technical terms to balance the
apparatus 1t is only necessary to move the primary
coil upon one of the chimneys to or further
away from its secondary coil. When so bal
iNictu uhe apparatus Is ready for use.
IT was found that Il lcaleu bullet in
its original form placed inside one of the chimnevs
so as to be close to the border of its secondary coil
made the ticking of the clock in the next room
family audible through the telephone 1t was from
tins point that tn" experiments of the two professors
began.
The work has difficulties which rcqnre great
patience and almost incredible Geli,acy of ohscrva-
ton to accomplish; for they are dealing with
feathcrwcights and hair-brcadths distances. The
line OF research IS entirely new one to eIcctri-
clans; but Professor Bell and Professor
10iutor accord to several other cui-
ncnt electricians the credit Of having
simultaneously with themselves, conceived
the idca of the possibility of maxim use Of The nrn
clpe discovered by Professor Hughes for tn. nm
pose to which it is now hoped to make ii arrli-
cable. Lead of all metals is, perhaps the least s,s
coptiblo Of nductivc effects from clcctlicitv 4
silver coin placed within the chimney made
ITS presence audible when it was an inch distant
from the secondary coil. A nattened bullet when
Its Hat side was presented 10 the coil gave an
audible result at distance about twice as great
Is that OK a bullet in its original form: while
q disk Of sheet lead gave greatly enhanced
results. Thus II was found that the mass of metal
I" De expermcnted with was matter of little rcla-
uFe consequence, while It's form and poStiun
t"hether its edge or broa lsie was prcscutcdl WAS
everything. delicate rejecting palvanolpctcr
being substituted for the telephone was found t he
not nearly 50 sensitive
Inc chief discovery hus far made is that a musi
eai tone or rather very rapid breaking and CLOSING
Oh the primary current, gives greatly incrcascl re-
SoltS through the telephone as compared with the
tcAinS OF the clock, and a vibrator which sends
100 ruisations second through the primary cir.
cult, has been substituted for the cloc, Tho
questions now TO be answered are numerous and
each ls being mace the subject of experiment
" ma; size of wire shOuld be used for the prim.r,,
and what Tor the secondary circuits to get III, hes
'nductive results What number of convolntiors
Ca III otAer terms what resistance should be given
10 either circuit What form should the coils take
'ui Mha' shoIid be their relative position How
bueh battery can be adyantageously used
Nohsiderabie progress has been made in several
'ne directions indicated by these questions The
"a results thus far obtained are from fiat urinary
'"iiS ABOUT two and one-half inches in diameter Inv
%o'e' 'nee-dnarters Of inch in thickness. each
NaVins i's secondary coil of much finer yvire
"''nin IL but made adjustable. SO they
can he lifted out partially or entirclv far tho NM