advantage to
employ round grains powder the tube,
and any event important that they
should uniform size and shape pos-
35 sible and that provision should made for
maintaining unchanging and very dry at
mosphere the tnbe. The conducting part e
50 good electrical connection with shaft S
and provided with tapering segments, /,
upon which slides brush which should
preferably capable longitudinal adjust
ment along the cylinder. adjust
ment the speed rotation the cylinder
and displacement the brush along the
axis the same the circuit may made to
65 open and close rapid succession and re
main open closed during such intervals of
time maybe desired. This tube
I rotate clockwork other means a
uniform and suitable rate spepd, and un
der these conditions find that this device
25 behaves toward disturbances the kind be
fore assumed manner similar that of
a stationary cell celenium toward rays of
light, its electrical resistance diminished
when acted upon the disturbances
30 and automatically restored upon the cessa
tion their influence. Another brush 6',
55 which connected the condenser-termi
nal T', being arranged bear upon the shaft
S, will seen that whenever the brush k
comes contact with conducting-segment e
the circuit including the primary will be
60 completed and the condenser, energized,
discharged through the same. The tubu
lar space between the plugs partially filled
with conducting sensitive powder, indi
cated, the proper amount the same and the
20 size its grains being determined and ad-
j usted beforehand experiment.5
685,956
or the air, and order apply this potential
difference effectively the sensitive device a
the terminals the same are connected to
two plates and P', which should as
5 large surface practicable and located
in the media that the largest possible differ
ence potential will produced the dis
turbances between the terminals the sen
sitive device. the
45 present case this device consists cylinder
made partly conducting and partly in
sulating material and e', respectively, which
is rotated the desired rate speed by
any suitable means. inductive relation
to the primaryp secondary coils, usually
of much thinner wire and many more turns
than the former, which are connected 70
series receiver illustrated ordinary
magnetic relay, continuously-adjustable
non-inductive resistance r", battery B'of a
properly-determined and very constant elec
tromotive force, and Anally sensitive device 75
a1of the same similar construction a,
which likewise rotated uniform speed
and which, with its brushes b", closes the
secondary circuit. The same may said the re
sistance r', which series with the bat- 95
tery and serves graduate the force the
latter, that the dielectric layers the sen
sitive device are -subjected similar
strain and maintained state delicate
poise. This device the present
io case one familiar construction, consisting
of insulating-tube, which indicated by
the heavy lines the drawings and which
has its ends closed tightly two conducting-
plugs with reduced extensions, upon which
15 bear two brushes through which the cur
rents are conveyed the device. The electromotive force
of the battery graduated means 80
the adjustable resistance that the dielec
tric layers the sensitive device are
strained very nearly the point breaking
down and give way upon slight increase of
the electrical pressure the terminals the 85
device.to pass
through, thus causing difference po- 125
tential the terminals and the con
denser. sufficient amount energy being
now stored this instrument during the
time interval between each two succeeding op
erations the device each closure the 130
primary circuit the latter results the
passage sudden current impulse through
the coilp, which induces corresponding cur- ■
rent relatively high electromotive force in
. will course understood that
the resistance used mainly because of
Convenience and that may dispensed
with, which case the adjustment may be
effected many other ways, deter- 90
mining the proper amount coarseness of
the sensitive powder varying the dis
tance apart the metallic plugs the ends
of the tube. the terminals T
and the condenser connected coil
p, usually consisting few turns con-
40 ductor very small resistance, which the
primary the transformer before referred
to, series with device which effects the
discharge the condenser through the coil
p predetermined intervals time. 100
The various instruments being connected
and adjusted the manner described, will
now readily seen from the foregoing that
under normal conditions, the device being
unaffected the disturbances, practically 105
so, and there being only very insig
nificant amount energy stored the con
denser, the periodical closure the primary
circuit the transformer through the opera
tion the device will have appreciable no
effect upon the primary coil and hence no
currents will generated the secondary
coil least not such would disturb the
state delicate balance existing the sec
ondary circuit including the receiver, and 115
therefore the latter will not actuated by
the battery B'; but when, owing the dis
turbances impulses propagated through
the media from distant source, addi
tional electromotive force, however small, 120
Created between the terminals the device a
the dielectric layers the same, unable to
support the increased strain, give way and
allow the current the battery
