The morning news. [volume] (Savannah, Ga.) 1887-1900, 1900-01-22


years mas been working on the problem
OF wireless telegraphy without intermls-
sion. Most of his experimental work
mas been carried on in England since
July, 1896, and it may be of interest TO
state that on his arrival in that country
ne received a rather rude welcome by hay
ing his instruments broken up and de-
sToyed by ignorant custom house otlclals
who mistook them for internal machines.
The creditable results so far obtained by
Mr.. Marconi, both abroad and in this coun-
| Try, are unquestiOnablv due to the apDara-
tus of which he makes use. The device
oy means of which the signals are sent,
or the transmltter as il is called. IS what
IS known as an induction coil. This con-
slsls of cylindrical bundle of soft iron
wires, upon which two separate coils of
insulated wire are carefully wrapped. The
first of these coils. Of reasonably heavy
wire and of one or TWO layers in depth
only, IS known Us the pr mary while
the second wrapping, consisting Of very
many turns Of fine wire is called the
secondary In the Marconi transmit
ter the primary winding of the coil IS con-
nected with nun 1er of dry batteries.
such as are employed for beli-ringing pur-
poses and with an ordinary Morse tele-
graph key, thus making a complete cleo
tric circuit, while the secondary winding
is connected to two brass balls about an
lnch and one-half in diameter, which are
placed about an inch and one-haf from
two larger brass balls whose inner hems
pheres, separated from one another by the
thirtieth of an inch. are inclosed in
| heavy rubber tube flied with oil. To one
of the small brass balls is attached YER
teal conductor anywhere from twenty to
200 feet in hight, depending on the dis
lance it is desired to transmit a message,
while the other small brass sphere is con-
nected by means of a similar wire with
the ground.
When the telegraph key in the primary
of the induction coil is closed an electric
current flows through the circuit and Gre
ates very great difference in electrical
pressure in the secondary winding and
thereby causes sparks TO pass across be-
tween all your balls and through the oil
bath. In other words, the action much re-
sembes discharge of lightning, only of
course on miniature scale These dis
charges create the electrical waves already
referred to as having been discovered by
Hertz, which oscillations may be sent out
into space in the form of Ions or short
waves by holding down the telegraph key
for a longer or shorter interval. In this
way ordinary Morse Geographic signals,
consisting of long and short strokes or
dots and dashes, are sent out in the form
of electrical vibrations
Now. in order to receive these signals
intelligently, recourse is had to Branly's
invention. This consists as already stat
ed, of what is known as a coherer or a
small glass tube about an inch and a. half
in length and one-thrtieth of an inch in
ternal diameter, fitted with two plugs of
| silver 10 which platinum wires are solder
ed, the remaining space in the tube be-
ing filled with a mixture of nickel and sill
Yer filings This sensitive tube is con-
nected in a circuit with an electric bat
terry a high resistance telegraph relay and
, sounder
Under normal conditions the filings In
the coherer will not allow of the passage
of the electric current from the local bat
terry, but as soon as the electrical wave
sent out from the transmitter strikes a
vertical wire similar to that on the send
ing instrument and connected with the
tube the filings, 50 TO speak, weld them
selves together or cohere and allow the
current to pass for a longer or shorter
| interval, depending on the length of the
wave sent. This current in flowing around
! the circuit operates the relay and sounder
and enables either a dot or a dash to be
| recorded. ,..
1t is found. however that when the fill
| ings in the tube have responded to a wave
| from the transmitter, they remain welded
! together until such time as the tube has
| been struck a smart tap, when the filings
| loosen up or decohere and the tube returns
| again to its state of high resistance
| Now, in order to transmit Morse signals
| it is manfestly evident that some means
| have to be devised for tapping the tube
| automatically For this purpose Mr.
| Marconi makes use of a little vibrating
! hammer attached to the sounder, which
! after every wave automatically strikes
| the tube a sharp blow thus Ioosening the
| filings ard permitting another wave to be
| recorded.
With the apparatus described a speed Of
! about twenty words a minute is obtain
| able, and ny employing in every case the
high vertical wire which intensifies the
| wave effect and which is original with
| Mr.. Marconi the latter has gradually sue
ceeded in increasing the distance over
which ineligible messages can be sent
! from three miles in May. 1897 to over
eighty miles in September. 1909
The principal defect in this system Of
! telegraphy is that as the electrical waves
! which emanate from the transmitter when
| space in all directions they affect every re-
/ ceiver that lies within the area of their
! influence. Thus, for instance, were mes
/ sage intended for Newark sent from New
! York, it would likewise be recorded at
/ Poughkeepsie, New Haven and other
! points, ASSUMING. of course, that receivers
/ in proper adjustment with the transmitter
/ were placed in those cities. To overcome
/ this difficulty, Mr.. Marconi, it is undc
! stood 5 81 work upon a reflector. by
| means of which he hopes to be able 10
/ project the electric waves in an almost
]
! zion, in much the same way that the rays
| of a searchliCht are focused. How far this
! will prove elective remains to be Drove1
! by subsequent experiments. but ii is safe
| 10 sssert thar before the Marconi system
/ of tclography can be adopted on anything
! like an extensive scale some scheme viii
| have 10 be devised whereby a massage IN
| tended for a certain locality win be record
! ed there and there only.
The question which naturally arises is,
| What future use will be made OF this
method Of transmitting signals? Tha,
! wireless telegraphy will ever replace the
method of biography now in general use
for commercial purposes is scarcely like
ly. owing to the apparently insurmoun a.
! BILE defect just referred TO. on the other
! hand, such system should prove of great
value in certain cases, as for instance n
communicating between lighthouses AMI
the mainland, in warning a vessel of the
| nnnrnnrh If annther during a fog. In sen1-