The San Francisco call. [volume] (San Francisco [Calif.]) 1895-1913, 1895-09-08

LAMPS LIGHTED BY
ELECTRICAL FISH. -
M. d'Arsonval, the well-known electri-
clan, has been doing some extraordinary
things in the way of demonstrating the
electric discharge of the torpedo fish. His
experiments, which were made before
the French Academy of Sciences
were so astonishing as to almost
suggest that the central station of
the future may be a huge and we'll
populated fishtank. Several special in
struments were used for recording the
phases of the discharge from the fish. One
was modification of movable circuit
galvanometer, consisting of light alumni
mum coil, upon which was wound the cir
cult traversed by the fish current. This
coil was attached to the center of a rubber
diaphram, stretched on Marcy air-drum,
which was connected by rubber tube to a
second smaller drum, carrying short
recording needle moving on smoked
cylinder. Another testing instrument is
composed of silver wire tenth of a
millimeter in diameter and 40 or so cent?
meters long. AS it is stretched horl-
zontally between two rigid supports,
its center connects with a second wire
held up by rubber spring and carrying
needle moving on the recording cylinder.
The torpedo is placed on plate with
metallic bottom, on which is left about
an inch of sea water to enable the
fish to breathe during the expert.
sheet of tinfoil in the shape
of the electric organs of the fish, placed
on the dorsal surface of these organs, and
joined by band of tinfoil centimeters
long. Thus the lower metallic plate
constitutes the negative electrode, and
the tin strips form the positive electrode
of this living electro-motor. The electrodes
are then united in the various apparatus
| for measuring or rendering visible the dis
charge of the organs. The demonstration
is opened by pinching the edge of the inns
of the fish with pair of dlssecting
discharge; but the torpedo is not OF
patient disposition, and if he is pinched
| hard he loses his temper and plies his
| electrical artillery vigorously and rapidly.
The discharge appears to be continuous,
| but in reality it is composed of six to ten
fish is always positive and the belly always
negative. IL seems difficult to believe
that the electric current from one of these
fish will not only light ordinary lamps,
| but burn them out; such, however, is the
fact. Torpedoes of a foot in diameter,
which had been kept in tank for week,
| had an electromotive force of from eight
to seventeen volts and an intensity of be-
| tween one and seven amperes. M. d Ar
| sonvaI took an incandescent lamp, cor
Stunning four volts and one ampere, and
| connected it to one of the electrical organs.
AS the fish was squeezed the lamp was
brilliantly lighted. DArsonval counsels
the experimenter to press the fish very
| lightly. In his first experiments he used
| unnecessary pressure and the fish dis
charged such current that his lamps
were all burnt out. Lamps placed on each
| organ lighted at the same time, with the
| same intensity, although on different cir
cults. The organ, however, soon exhausts
| itself, and requires rest before it is again
available. M. d 'Arsonval is now at work
| on experiments for establishing com parl-
son of the respective electrical powers of
the torpedo, the gymotus or electric eel
| and the electric cat.
The PEOPLE THAT WALKED IN DARK
NEss.-In these days of cheap gas it is sell
dom one hears of an abrupt transition from
the oil lamp to electricity for the lighting
of streets, but that such change is impend-
ing in remote village in Rhode Island
| has been announced by correspondent.
Either the old lamps must have been very
| few and far between, or the oil very bad,
/ lO1 bAc flldSClo say tuCy AdNC hltuCl W
walked in darkness and are elated at the
great light that is soon to burst on them.
| What the feeling about this important
event is in the village may be gathered
! from the following extract from the local
press: mystic is to have street lights.
| The powers that move for the upbuilding
| of the pretty valley have decreed it;
her sons and daughters have offered their
| talents to push along the scheme; and the
! balance of the population are waiting
anxiously for the opportunity to pour their
! dollars into the Golfers of the box-office
when the opera Priscilla is produced.
John Alden himself, in his historical 81
| lence when vital question was concerned,
| was not as dumb as the streets of Mystic
| have been, when, time and again, Egypt
| ian darkness should have moved even the
stones to cry out. But no more will the
granite curbstones and rocky hillocks wait
| in mute silence for their victims; no more
will the damp, muddy places smile upon
the doctors profession; no more will the
animal kingdom have cause to doubt its law
full rightto the streets Not more welcome
| to the heart and life of John Alden was
the incoming of Priscilla to brighten and
bless than will be the income of this new
Priscilla with the promise of Frightening
and blessing the dear old town we all love
so we'll So here's for long pull, and a
strong pull, and pull all together, for a
/ SlOIlOuS SuCCCSos
ELECTRICAL LrBRARrAN.-The new Boston
| library has made a notable adaptation of
electrical devices in the handling of books.
a system has been designed by which an
attendant on the main floor has only to
pick out the book wanted, put it In rail-
way car. with cable attachment, put it off
the side switch to the main line and let it
travel around at the rate of 500 feet a min
ute to a special elevator, which drops au-
| tomatically, as soon as the car is in posi-
ton, down to the delivery-room.
When the entry has been made the
car, which has been waiting, rolls
back with its load on re-
| turn track, to the switch from which it
started. For the accommodation of the
hundreds of thousands of volumes, the |
books are distributed throughout six |
stories. The aim of the designers was to |
/ focus all the books toward central |
point, to facilitate delivery. An elevator |
well, long and narrow, which pierced the |
entire building from basement to roof, was |
constructed, and in this were set up shafts |
for thraa oil Those aIayaforc ORC |