Evening star., 1902-02-22
WIRELESS TELECRAPHY
Ours the Only Navy With
out Apparatus.
EXPERIMENTS M ADE
REAR ADMIRAL BRADFORD'S
/. TALK TO NAVAL COMMITTEE.
Ether Waves Will Some Day Bear
Tidings Of Naval Wars-Ap-
preparation Asked.
EXPERIMENTS MADE

The United States navy is practically the
only navy in the world which is not using
some method Of wireless telegraphy. The
present experimental stage of this new art.
however, is the reason rather than any lack
of enterprise. Experiments have been, and
are now, being made by the Navy Depart
ment, as well as other branches Of the gov
ernment.
Just what has been accomplished, as well
as what may reasonably be expected to be
accomplished in the future, in this direc-
tion recently outlined to the House
committee on naval affairs by Rear Admi-
raj r. B. Bradford. chief Of the bureau Of
equipment of the navy. AS a result an ap-
preparation expressly for the purpose OF
wireless telegraphy equipment will doubt
less be one Of the new features of the forth
coming appropriation bill. Admiral Brad
ford's account of what has been done, as
well as his explanation of the principles of
wireless telegraphy, is most interesting.
On this subject he said
Not Entirely Marconi's Invention.
Ships Of all continental naries.' said
Admiral Bradford, 'are being supplied
with wireless telegraph apparatus; also, to
some extent, those Of the small navies Of
South American countries.
1T is a popular idea that the system is
entirely the invention of Mr.. Marconi, and
that he has a monopoly of effective appl
ances for the purpose. This, however, is
an error At present the apparatus is man
ufactured by two firms in Germany, two
In Paris and one in London the latter be-
ing the Marconi company. Mr.. Marcon1
has patented certain apparatus in England,
but 1t Is doubtful IL these patents would be-
sustained by the courts There are GER
tain companies in the United States that
have patented inventions in connection with
wireless telegraphy. There is no company,
however, in the United States, so far as l
am aware. that is today prepared to pro-
vide wireless telegraph apparatus for use or
experiment; the policy of the American
companies appears to be chiefly to control
patents for money-making purposes.
The English and Italian navies use the
Marconi apparatus; the Russian and French
Eayies a French apparatus; the German
navy a German apparatus. Other nayies
purchase Unfortunately from various
firms. evidently for testing purposes.
A complete set Of wireless telegraph ap
paratus. sufficient TO provide one station
with both transmitting and receiving applf-
ances costs about 1000, both in Germany
and France. The Marconi Company sup
plies the same for about $1,000. but re-
quires a royalty of $500 year for period
or fifteen years.
Ships Supplied With Apparatus.
I'm addition to ships Of foreign nayies,
many transatlantic passenger steamers
have been supplied with this apparatus for
the purpose Of communicating with one an
other at sea, ani also for the purpose of
announcing. through shore stations. their
approach to or departure from land.
I'm the North sea, and to some extent
elsewhere. lghtships and shore stations
have been placed in communication with
one another by means Of wireless telegra-
ply. 1t is very useful for such cOmmunica-
tion and permits the masters Of distant
o fGhinG n
treSs. etc.
"The apparatus is by no means perfect
1t will not work in very hot weather; why
Is not fully known After the heat of the
day Is past. however messages are trans
mitted without difficulty. Messages can
be sent during fog and bad weather. AS a
matter of fact the transmission Of mes
sages is facilitated by the presence of fog
Cold weather does not seem to interfere
with its use. Communication. however, Is
as rule entirely interrupted during the
prevalence Of thunder storms.
when the transmitting apparatus at q
wireless station Is In operation no other
transmitting apparatus within its radius
of effect be used without conflicting
with the message being sent by the first
mentioned and rendering it entirely unintel-
ligible. This quality is known as 'interfer-
ence. and Is, of course, a very great draw
back. 1t Is claimed by some makers that
the difficulty of Interference may be over
come by tuning the apparatus used SO as
to create a certain syntony of waves. /
cal appliances accomplishing this result
have been devised. If all stations are under
the Jurisdiction of a single person this diff
ficulty can be arranged. While messages
may be received and read at all stations
within the radius Of effect Of the trans
mitter. message may be kept secret by
the use Of codes
Advantage at Sea.
ut will be readily understood what
great advantage this system Is at sea, as
it enables a ship to report her location and
condition or ask for assistance from other
ships many miles away (probably at least
60 to 1OO) without difficulty. Messages can
be transmitted over the sea with much
more facility than over the land. and
probably about twice as far. The range of
this apparatus for Ineligible signals is at
present unknown. 1t is being increased by
the use Of more powerful appliances.
Anotner Illustration may be made Of Its
| flagship Is anchored In Havana harbor,
with lookout vessels stretched across
Florida channel or across the Yucatan
channel or the entrance to the Gulf of
Mexico or all three combined she may
then receive reports at will Of any sus-
picous circumstance. the approach Of hos
| for effective action.
Perhaps l may convey to the committee
| general knowledge Of the principle in
volved In the use Of wireless telegraph ap-
- 40 DsASSN SiitNSl upOH the aDll1-
| ty OF an operator, with a certain delicate
| apparatus. to detect the arrival Of the So
called Hertzian waves, or electric pulsa-
| tions. which are radiated in all directions
| with the velocity of light on the discharge
| OF an ordinary electric spark These waves
may perhaps be best conceived by referring
| to the effect Of throwing a stone into the
center Of a placid and quiet pool. Just how
far they travel Is unknown: 1t probably de-
pends somewhat upon the intensity OF the
| electric spark: In fact this has been fairly
| we'll demonstrated. We are not 90 much
interested. however, in the tourneys 81
these waves as In the distance from the
! operator at which We can detect their nres
| ence. It is also fairly we'll established
| fact that Hertzan waves follow the surfa re
| OF the earth and are parallel to It.
| suppose we now erect on the surface of
| the earth near the transmitting station a
| vertical wire or other good conductor of
electricity; II insulated from the earth II
may be utilized to transmit a current Of
| electricity and discharge spark into the
| air.
| Apparatus Explained.
''For generating electric sparks the
Rhumkof coil il ordinarily used This you
| will probably remember as an old labora-
tory friend. An ordinary voltaic battery
| is used in connection with the Rhumkofr
| coil. To obtain a greater distance of trans
| mission, however. q dynamo ia used instead