eT 
FEBRUARY 5, 1914] 
NATURE 
647 
—chiefly carbon monoxide and nitric oxide, with 
small proportions of hydrocyanic acid. Mixed with 
air in suitable quantity, the evolved fumes are highly 
explosive; but the Committee found no evidence to 
confirm the opinion that celluloid itself is liable to 
spontaneous ignition at ordinary temperatures or is 
explosive in ordinary circumstances, 
A number of experiments were carried out at the 
Government laboratory for the information of the 
Committee. It was found that the ‘ fuming-off” 
test devised by Prof. Will was the simplest and one 
of the most trustworthy methods for ascertaining the 
relative stability of various kinds of celluloid towards 
heat. No definite relation between chemical composi- 
tion and stability to heat could be detected, though a 
small proportion of mineral matter appears to have 
a distinct stabilising effect. Celluloid contains suffi- 
cient oxygen to support its own combustion, and once 
ignited will continue to burn in the absence of air; 
chemical fire extinguishers using carbonic acid gas 
are, therefore, of little use, and water alone is the 
best means of extinguishing the substance when 
burning. The Committee makes a number of recom- 
mendations as to the storage and working of celluloid, 
with the view of lessening the danger from fire; for 
these the report itself should be consulted. 
WIRELESS TELEGRAPHY.! 
HEN Mr. Marconi first came over to England in 
1896, Mr. Swinton was the means by which he 
was introduced to Sir William Preece, and the latter, 
having just then come to the conclusion that his 
methods of inductive and conductive telegraphy—with 
which he had been attempting to effect communication 
with lightships—were unworkable, set the Post Office 
to work with Mr. Marconi, Sir John Gavey having 
charge of the experiments. It might seem strange, 
as Prof. S. P. Thompson had pointed out in Nature, 
that Sir William Preece missed the possibilities of Sir 
Oliver Lodge’s Hertzian-wave experiments, but took 
up Mr. Marconi with practically the same system. 
But Sir William Preece had always been particularly 
sympathetic to the young, and Sir Oliver Lodge had 
not approached him directly. 
Next, quoting from an article which Sir William 
Crookes contributed to The Fortnightly Review in 
1892, Mr. Swinton showed that Sir William Crookes 
had in those days fully realised the possibility of tele- 
graphy by means of Hertzian waves. He clearly 
described how messages might be sent in Morse 
alphabet by means of apparatus tuned to special wave- 
lengths and receivable only by apparatus similarly 
tuned. Mr. Crookes also referred to experiments 
made by Prof. Hughes in 1879, where wireless signals 
were transmitted over several hundred yards, at which 
experiments he had assisted. There seems to be no 
doubt that Hughes discovered Hertzian waves and 
noted their effects some years before Hertz re- 
discovered them, but, unfortunately, Sir George Stokes 
told Hughes, apparently quite erroneously, that the 
results could be explained by known induction effects, 
and Hughes was so much discouraged that he never 
published anything on the matter. 
Then, with reference to Sir Oliver Lodge, Mr. 
Swinton said that he would always regard him as the 
original inventor of wireless telegraphy, because Sir 
Oliver Lodge in his Royal Institution lecture in 1894, 
and later at the Oxford meeting of the British Asso- 
ciation in the same year, had first publicly sent signals, 
rung bells, and deflected galvanometers over a distance 
by means of Hertzian waves. It had been said that 
41 Abstract of the presidential address delivered to the Wireless Society of 
London on January 21 by Mr. A, A. Campbell Swinton. 
NO. 2310, VOL. 92] 
Sir Oliver Lodge did not make clear the telegraphic 
application of his experiments, but Mr, Swinton was 
present at Lodge’s Royal Institution lecture, and was 
so much impressed with the telegraphic capabilities it 
suggested, that he had next morning discussed with 
his then assistant, Mr. J.C. M. Stanton, the possibility 
of setting up communication between his residence in 
Jermyn Street and his office in Victoria Street by 
Lodge’s method. This experiment was never tried, 
as they had thought that too many large buildings 
intervened, but preliminary experiments were made in 
Mr. Swinton’s office, and signals on a bell were suc- 
cessfully transmitted and received through several 
walls with a large Tesla high-frequency coil used as 
transmitter, and as receiver a coherer consisting of a 
heap of tintacks. This was two years before Mr. 
Marconi arrived in this country, but in making these 
statements Mr. Swinton did not wish in any way to 
belittle the great work that Mr. Marconi undoubtedly 
accomplished in making wireless a practical and com- 
mercial success by long-continued and arduous labours. 
Passing to his experiments, Mr. Swinton stated that 
finding a difficulty in reading wireless messages by 
ear, he had devoted attention to automatic recording 
apparatus. A simple arrangement that he had devised 
was to employ a sensitive or manometric flame, such 
as can be made exceedingly sensitive to minute sounds, 
the flame greatly shortening and roaring the moment 
the smallest sound reaches it. 
Different descriptions of these flames respond more 
readily to sounds of different pitches, and they also can 
be tuned to some extent, so that different flames would 
discriminate between signals of different acoustical 
pitch even of the same electrical periodicity. All that 
was necessary was to place the receiving telephone in 
proximity to the sensitive portion of the apparatus 
producing the flame, and if a screen were placed in 
front of the latter hiding the flame when it was 
shortened, photographic records of Morse signals were 
easily obtained by throwing by means of a lens a 
small image of the flame when visible upon a moving 
strip of photographic paper. Another method of re- 
cording the signals employed by the lecturer was to 
arrange a quick-period mirror galvanometer with the 
movable portion oscillating between adjustable stops, 
the oscillations being recorded on a strip of moving 
photographic paper by projecting on the latter the 
reflection in the oscillating mirror of a bright point of 
light proceeding from a pinhole in an opaque box, 
containing an electric lamp. 
Operating, as he did, at his own house, with a very 
small aérial, Mr. Swinton, in order to magnify the 
signals, made use of several relays of the types in- 
vented by Mr. S. G. Brown. He showed three of 
these relays connected in series, actuated by signals 
received on a temporary aérial that Messrs. Gamage 
had kindly erected on the roof of the Institution of 
Electrical Engineers. The relays operated a Kelvin 
siphon-recorder, as well as a loud-speaking telephone, 
which could be heard by everyone present. At a 
quarter to nine o’clock a special congratulatory message 
was received. This was sent by Commandant Ferrié, 
a vice-president of the society, from the Eiffel Tower. 
Not only could every signal be clearly heard through- 
out the Lecture Hall, but it was also received on the 
siphon-recorder. Further, the motions of the siphon 
were made visible to the audience, being optically 
projected on a screen with the aid of an Epidiascope, 
kindly lent by Messrs. Leitz and Co. The dots and 
dashes were easily read, both audibly and_ visibly, 
though the Admiralty in London was accidentally 
during part of the time sending radio-telegraphic 
signals, which were likewise made audible by means 
of the loud-speaking telephone. The message from 
