SEPTEMBER 8, 1899. ] 
annum. The examination will be held on Sep- 
tember 17th, 18th and 19th. 
LorD KELVIN writes to Nature from Aix-les- 
Bains under the date of August 7 as follows: 
‘Last night, during a thunderstorm of rare 
severity in which brilliant flashes —single, 
double, triple or quadruple — followed one 
another at intervals often of not more than a 
few seconds of time, I was surprised to see, 
with great vividness, on a suddenly illuminated 
sky, two nearly vertical lines of darkness, each 
of the ordinary jagged appearance of a bright 
flash of lightning. I remembered to have seen 
two real flashes of just the same shapes and 
relative positions, and I concluded that the 
black flashes were due to their residual influ- 
ence on the retina. I turned my eyes quickly 
from the dark sky outside to an illuminated 
wall inside the house, and I again saw the 
same double dark ‘flash,’ which verified my 
conclusion in an interesting manner. The 
fatigued part of the eye failed to perceive the 
brightness of the sky in the one case and of the 
wall in the other.”’ 
In the course of an interview with Signor 
Marconi, a press representative obtained some 
information with reference to the arrangements 
for the wireless telegraphy demonstrations at 
the forthcoming meeting at Dover of the British 
Association. The headquarters of the British 
Association will be at the Town-hall, and it is 
here that the French and English scientific 
visitors are to have the opportunity of witnes- 
sing some wireless telegraphy experiments. 
Signor Marconi had just returned from the 
naval manceuyres, and planned to leave for 
America at the beginning of September. He 
would, however, superintend all the neces- 
sary arrangements for his demonstrations at the 
British Association. During the meeting these 
demonstrations will be left in charge of Profes- 
sor Fleming, of University College, London. 
Messages of congratulation will probably be 
exchanged between Dover and different parts 
of Europe. Signor Marconi said that the trials 
between Dover Town-hall and the lighthouse at 
St. Margaret’s had been a complete success, the 
tests applied yielding the most satisfactory re- 
sults. Asked as to whether an attempt would 
SCIENCE. 
43 
(oy) 
be made to send messages direct between Dover 
Town-hall and Boulogne, Signor Marconi said 
this would depend upon circumstances. The 
installation at Wimereux, near Boulogne, is the 
property of the French government. It was 
possible to send direct communications, but cer- 
tain alterations on the French side of the Chan- 
nel would be necessary. As the French Asso- 
ciation for the Advancement of Science would 
be holding its annual conference at Boulogne 
at the same time as the British Association at 
Dover, and as both societies would be cooper- 
ating together and exchanging courtesies, he 
thought there should be no difficulty in obtain- 
ing the necessary consent of the French gov- 
ernment. Otherwise messages will be sent 
across the Channel between Dover and Bou- 
logne via the South Foreland. Signor Marconi 
referred to the demonstrations with wireless 
telegraphy made during the recent naval ma- 
neuyres. The results of these demonstrations, 
he stated, had established the fact that, even 
with the present installation at the South Fore- 
land lighthouse, messages could be exchanged 
with a fleet as far down the Channel as Cher- 
bourg, a distance of about 100 miles, and even 
farther. 
THE London Times states that several mem- 
bers of the expedition organized by Mr. Claude 
Beddington for scientific and geographical re- 
search in West Africa have returned to Eng- 
land. The route followed by the explorers 
lay through the Hinterland of the Gold Coast, 
the neutral zone (the delimitation of which is 
now the subject of diplomatic negotiation), 
and the Hinterland of the German colony, Togo- 
land. Many districts hitherto unvisited by 
Europeans were traversed, and several new 
and interesting entomological specimens have 
been the result of the explorer’s enterprise. 
The big game encountered included elephant, 
buffalo, hippopotamus and many rare species of 
antelope. Mr. Beddington was much struck 
with the enterprise shown by the German gov- 
ernment in Togoland, where well-constructed 
roads and substantial goverament buildings, the 
result of large Imperial grants, form a striking 
contrast to the condition of things in the British 
territory. Among other industries encouraged 
by the German authorities is the planting of 
