648 
the Eiffel Tower consisted of thirty-four words, and 
occupied about seven minutes. A congratulatory 
message was also received and rendered audible to the 
audience from the London Telegraph Training Col- 
lege at Earl’s Court. 
Mr. Swinton also showed the working of an ordinary 
Morse inker by means of wireless signals from a 
distance. For this he employed the three Brown 
relays with a Siemen’s Post Office relay in addition. 
The inker was modified by turning the magnets 
upside-down, so that when energised they pulled the 
inking wheel away from the paper tape, and the 
signals were recorded when the magnets let go of the 
armature instead of when they attracted it, as is the 
usual arrangement. Mr. Swinton had devised this 
method to get over the difficulty of the extra current, 
due to the relay breaking the magnet circuit, sending 
a wireless signal back to the whole apparatus, With 
the modified arrangement this extra signal took place 
while the main signal was being received, so it could 
only accentuate the latter and do no harm, whereas 
before the modification was effected, when once 
started, the Morse inker went on working by itself 
like an electric bell. : 
Next the lecturer showed how it was possible to 
receive wireless signals on a phonograph. In the 
ordinary way, records made by this method were not 
loud enough to be heard by an audience, but a small 
microphone had been mounted on the repeating 
diaphragm, and connected to a loud-speaking tele- 
phone, and by this means signals from the Eiffel 
Tower and from the Admiralty, which had been re- 
corded on the phonograph, were made audible through- 
out the hall. 
Once an arrangement of relays that would work a 
Morse inker was provided it became possible to 
operate almost any kind of apparatus, and wireless 
signals sent by the British School of Telegraphy at 
Clapham were made, by means of the relays and an 
electromagnet, to work an air-valve in connection with 
a source of air pressure and an organ pipe, which 
latter gave forth in long and short blasts the signals 
of the message. Mr. Swinton said that the same 
apparatus worked a motor-horn very effectively, but 
the horn could not be used indoors, as its noise upset 
the relays. 
Next it was explained how a Poulsen telegraphone 
could be used as a recorder; and that on the Poulsen- 
Pedersen system an Einhoven ‘string’? galvanometer 
was employed for this purpose. With this instrument 
a signal containing energy to the extent of only one 
billionth of a watt could be registered, which is about 
the same sensibility as what is obtainable with a Bell 
telephone receiver. On the assumption that a 
12 candle-power light, radiating one watt in the form 
of visible electromagnetic waves, was visible at a 
distance of five miles, and that the aperture of the 
eye was one-fifth of a square inch, then the amount 
of power reaching the eye would be about one-sixth of 
one billionth of a watt, so that natural detectors like 
the eye, and artificial detectors, such as the Einhoven 
galvanometer, had about the same order of sensitive- 
ness, and were much more sensitive than any photo- 
graph process for instantaneous eflects, although 
photography had the advantage that cumulative effects 
could be obtained by long exposures. Some years 
ago Lord Rayleigh found that the human eye and ear 
were of the same order of sensitiveness. 
Another matter mentioned by the lecturer was that 
the Eiffel Tower aérial, as also those at Poldhu and at 
other large stations, gave out loud sounds when mes- 
sages were being transmitted, this being probably due 
to the air particles being electrified and repelled, as in 
a Brush discharge. 
In his concluding remarks, Mr. Swinton speculated 
NO. 2310, VOL. 92] 
NATURE 
[FEBRUARY 5, 1914 
on the future of wireless. The chief difficulty at pre- 
sent with regard to wireless telephony is to get a 
microphone that would carry sufficient current without 
burning up, while there is also the necessity for 
switching over, when changing from receiving to — 
transmitting, which renders conversation troublesome. 
These are, however, difficulties that should be got 
over, and it was probable that in the not far distant 
future, we should have statesmen wirelessly addressing 
numerous audiences simultaneously, while wireless 
receiving stations would be set up in connection with 
halls where people would be able to go and hear viva 
voce all the prominent speakers of the day. Further, 
wirelessly operated column printing telegraphs would 
tell the latest news to all the nation, as also to any 
newspapers which continued to survive this much more 
rapid method of disseminating intelligence. Again, if 
we are ever to have Transatlantic telephony, it would 
probably be wireless, with which the difficulties due 
to the capacity and self-induction of the cables are 
avoided. ‘ f 
Mr. Tesla and Prof. Pedersen even believe in the 
possibility of wireless transmission of power, and in 
this connection it must be remembered that practically 
all the power on our planet comes from the sun in 
the form of electromagnetic waves, and amounts, on 
a clear day, to no fewer than 4,500,000 horse-power per 
square mile of the earth’s surface. This is, at any 
rate, good evidence that enormous amounts of power 
can be transmitted over prodigious distances by means 
of electromagnetic waves, but it is difficult to imagine 
how efficiency could be obtained. 
Finally, Mr. Swinton appealed to the romance 
attendant on the spectacle of great liners hurrying 
across the ocean to the assistance of a ship from whom 
they had just heard in wireless whispers the S.O.S. 
signal of distre:s. 
UNIVERSITY AND EDUCATIONAL 
INTELLIGENCE. 
Campripce.—The General Board of Studies will 
shortly proceed to appoint a University lecturer in 
mathematics and a Cayley lecturer in mathematics in 
succession to Dr. Baker, the new Lowndean professor, 
who held both of these posts. 
Mr. A. H. Cooke, of King’s College, and Mr. H. H. 
Thomas, of Sidney Sussex College, have been approved 
by the General Board of Studies for the degree of 
Doctor of Science. { 
The council of the Senate have issued an important 
report on the admission to University lectures and 
laboratories of men who are not members of the Uni- 
versity. The success of the diplomas in agriculture 
and in tropical medicine and in other subjects, has led 
to a considerable increase in the number of students, 
not members of the University, who are using the 
University laboratories and lecture-rooms. It is pro- 
posed in future to keep a register of such students 
and to charge each of them a small fee. 
Mr. L. G. Sutron has given a donation of roool. 
to the fund which is being raised to provide adequate 
buildings and laboratories for the agricultural and 
other departments of University College, Reading. 
Tue sixteenth annual dinner of the City and Guilds 
College Old Students’ Association will be held at the 
Trocadero Restaurant, Piccadilly Circus, W., at 7.30 
p-m., Saturday, February 21. Dr. G. T. Moody, 
president of the association, will occupy the chair. 
Tickets may be obtained by any old student of the 
college from Mr. G. W. Tripp, 4 Fairfield Road, 
Charlton, Kent. 
Tue legacies of the late Lord Strathcona include the 
- following to educational institutions :—St. John’s Col- 
