New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1903-08-03
TESLA'S TUNING PLAN.
1T ASSURES SECRECY.
din AdUance an Wireless TeIegrdphy
-MeddHng impossible.

Any one who has ever tried to persuade Mr.
Tesla to talk for publication about his expert
lnents and projects knows how firm and eour-
teous are his refusals. Nevertheless one source
of information about his inventions is open to
the public. His patents are matters of record
ANY one may obtain copies by proceeding in the
right manner, though familiarity with legal
phraseology and electricity is necessary fully to
understand them. Two patents. almost identical
in tenor. were recently issued to Mr.. Tesla.
The invention which they cover seems to con-
stitute distinct Improvement in wireless teleg-
raphy and its character and purpose are per
fectly inteIligible.
Almost from the first it has been apparent
that that system of communication would have
a limited application unless secrecy could be
insured Hence. several of the most conspicuous
workers in this field have been studying how to
attain such a result. While their methods diff
fer in detail they all agree that the problem
IS TO be solved by tuning BY that phrase
electricians mean a regulation or adjustment
Of the transmitter which makes it send out
waves Of certain frequency-say 100000 a
secondhand a treatment of the receiving ap-
paratus which renders the latter more suscepti-
bic TO that number than to any other. 1t has
heen assumed, rashly perhaps, that unless
!.iratically disposed outsider either knew what
frequency was being used, or hit upon it by ac-
cident. he could not adjust his instruments so
that he could steal message where tuning
had been employed. Of course. where no at
tempt was made to insure such agreement, wire
less communications would not be private. In
some kinds of service, indeed-as between
steamships meeting ar sea-no harm would
suit from overhearing.
In his patent specification Mr. Tesla points
out difficulty which is experienced in the oper-
alton just described, and which he has sought
10 evade. a phenomenon is observed in the
generation of electric waves which parallels
one IN music. II a given tone is produced by
violin string, several others. less audible. will
also be emitted II that tone be the one which
IS caused by one hundred vibrations second
the additional but fainter sounds viii be those
resulting from 200, 300 and other frequencies
Such extra tones. 'harmonics." represent
exact multipIes OF the number of vibrations
requisite to the lowest, fundamental, one,
and there are usually six of them. When a
Hertz wave generator is put in operation that,
too produces ''harmonics." Besides the one
principal frequency which the operator aims to
employ, his apparatus viii also give out multi
Piles. Mr. Tesla declares that a receiver which
has been regulated TO respond 10 one frequency
is likely pick up waves which are given off
anywhere from exactly twice TO exactly seven
times as often. Hence it might receive mes
TEN OF tuning, therefore, seems less secure than
Is desirable.
Mr Tesla's plan certainly appears distinctly
superior 10 this. What he proposes to do is to
generate TWO or more sets of waves at once, and
employ them. all simultaneously in sending.
These might have frequencies proportioned TO
zach other in some such fashion as 13 and H.
,r - and A. or 73. 50 and 101. Only a receiver
which had been tuned TO respond to two or three
elected rates of vibration when all were in use,
would be able 10 pick up a message thus sent.
II will be seen at a glance that this scheme
offers from the other very much as the many
notched Yale key differs from an ordinary latch
key. Though Mr.. Tesla thinks that only two
frequencies would usually be enough, the sys-
TEN admits of considerable multpcates. More
over. it may be taken for granted that the
mechanism used would admit OF a quick altera-
lion Of the selected frequencies, like that Of the
numbers Of a combination for a bank safe lock.
another advantage may result from this in
yention besides that Of secrecy. 1t may avert
rnischevous interference Some years ago, when
preparations had been made for reporting the
interna tional yacht races off Sandy Hook the
following incident occurred: A press boat went
down the Bay. a day two in advance, to test
its apparatus. and began sending messages to
land. Persons on another boat, with similar ap-
paratus, sent out signals at the same moment In
consequence there a confusing tumble OF
letters at the receiving station. One message
overlapped the other. A few weeks ago, while
Or. Fleming was giving lecture in London to
prove how beautifully the Marconi tuning"
system worked, Nevil Maskelyne sent in Rats
and other inappropriate remarks from a point
outside and the speakers instruments recorded
them. much to his embarrassment
only last week DR.. Slaby, the author of one
of the German systems Of wireless telegranhv
openly avowed his belief in the propriety Of in
ierferng with the receipt Of Marconi messages
in England by sending out a continuous stream
Of signals with a powerful transmitter on the
German coast. Finally, Il is interesting to
speculate for about ten seconds as to what
would happen at Cape Cod t. while Marconi
was trying TO send thither from Poldhu Mr.
Tesla were TO start up his generators at War
dencliffe. The South Wellheet receiving oper-
ator's hair would probably turn gray with per
plexity IN the effort to decpher the conarnunica-
lions that actuated his instruments
Quite aside from the morality Of such conduct
(Which might depend circumstances not
known 10 the public. it seems TO be entirely
feasible Apparently too, a receiver which has
been adjusted to respond to Mr.. Tesa's COM
hiration would be immune against any amount
r, outside interference. Time only can tell the
full value Of his latest patents, but an unpreju-
diced Judge can easily see immense possibilities
= Tho idea