490 
Technical Problems. 
The tropical crops which chiefly claimed the atten- 
tion of the congress were rubber and cotton, one day 
being devoted wholly to the former and one and a half 
days to the latter. A good deal of discussion took 
place with regard to the alleged variation in the 
properties and quality of plantation Para rubber. The 
discussion made it clear that at present each manu- 
facturer seems to have set up for himself an empirical 
standard of quality for plantation rubber, and that it is 
very desirable that some generally accepted standard 
should be adopted. A number of papers on the cul- 
tivation of Ceara, Castilloa, and other rubber-yielding 
species in various countries were also read, and 
Messrs. Petch and Green contributed interesting and 
useful papers on the tapping of Hevea and on the 
insect pests of Hevea respectively. 
A series of papers on cotton was read dealing with 
almost every phase of this important subject, such as 
the breeding of new cottons, the selection of cotton- 
seed, the technical qualities which manufacturers re- 
quire in new cottons, the methods of investigating 
cottons, and so on. One of the most interesting con- 
tributions on cotton was that by Lord Kitchener 
describing the successful reclamation of a large area 
of salt land in the Egyptian delta and its utilisation 
for cotton growing. Equally useful was the address 
delivered by Mr. Harcourt, Secretary of State for the 
Colonies, describing the work of the Imperial Insti- 
tute, the British Cotton Growing Association, the 
Colonial Departments of Agriculture and other bodies, 
which under the direct control of the Colonial Office, 
or with its active sympathy and support, now further 
in every possible way the cultivation of cotton within 
the Empire. 
The various subjects alluded to above occupy such 
an important place in every tropical country that a 
large proportion of the time of the congress was 
devoted to them, but time was also found for the 
discussion of a number of subjects which are of special 
importance to certain countries. Thus Prof. Carmody, 
of Trinidad, contributed a most interesting account of 
the experiments on cocoa cultivation and preparation 
now in progress in that island, and useful contributions 
on this subject were also made by Messrs. Johnson, 
Tudhope, van Hall, Booth and Knapp, and others. 
Wheat is as yet scarcely regarded as a tropical crop, 
and Mr. A. E. Humphries’s paper on the possibilities 
of wheat production in the tropics, no less than that 
of M. Baillaud on the wheats of Tunis and Algeria, 
was a revelation to many members of the congress 
of new and unsuspected areas suitable for wheat cul- 
tivation. 
Herr Hupfeld’s paper on the oil palm in the German 
colonies was another contribution of which special 
mention may be made, since it gave an authentic 
account of the actual operation of European machinery 
in West Africa in the extraction of palm oil, an innova- 
tion which is likely to revolutionise this immense 
industry, which has hitherto been conducted by natives 
using most primitive and wasteful methods. 
In conclusion mention may be made of the hos- 
pitality extended to the members and delegates. H.M. 
Government gave a dinner to the foreign delegates 
and a reception for all the members and delegates on 
the evening of June 23. Both these functions took 
place at the Imperial Institute. On Saturday, June 
27, a selected party of members and delegates was 
invited by the Duke of Bedford to visit the Woburn 
Experimental Farm, and by the Lawes Agricultural 
Trust to visit Rothamsted. The party exhibited great 
interest in the experiments in progress at both stations, 
which were explained to them by Mr. S. U. Pickering 
NOL 2232 WOLTOsl 
NATURE 
[JuLy 9, 1914 
and Dr. Russell. A party also visited Kew on the 
same day on the invitation of Sir David Prain. During 
the week receptions were held by the Royal Geo- 
graphical Society, the Royal Colonial Institute, and 
the Rubber Growers’ Association, all of which were 
largely attended by members and delegates of the 
congress. 
INTERNATIONAL COMMISSION FOR 
SCIENTIFIC RADIO-TELEGRAPHIC 
RESEARCHES. 
oe idea of forming an International Commission 
for the scientific study of questions relating to 
wireless telegraphy arose from a conversation between 
Prof. Schmidt and Mr. Goldschmidt, at the Inter- 
national Time Conference in Paris in 1912. Repre- 
sentatives from various countries held a meeting in 
Brussels in October, 1913, at which a provisional com- 
mittee was appointed and the general lines of the 
scheme for the organisation of the working were 
drawn up. 
power station at Laeken, near Brussels, radio- 
telegraphic emissions at regular intervals, and that 
these emissions should be observed and measured by 
experimenters in Belgium and in other countries. 
The commission held a sitting on April 6 at 
Brussels, under the presidency of Mr. Duddell, at 
which the commission was constituted definitely. The 
results already obtained were discussed and arrange- 
ments made for future experiments. 
National committees, which formed part of the 
organisation of the International Commission, have 
been constituted in Belgium, France, and Great 
Britain. In Germany, many stations have agreed to 
receive the signals, and a more complete organisation 
will be formed soon. National committees are also 
in course of formation in Austria, Russia, Italy, 
Switzerland, etc. 
At the last meeting it was decided to cooperate so 
far as possible with the work of the Committee for 
Radio-telegraphic Investigation of the British Asso- 
ciation, and the scope of the work was set out. 
A demonstration of the methods 6f emission and 
measurement in use at the high-power station at 
Laeken, Brussels, took place before the commission, 
and reports were read on changes that had been made 
and on future alterations. The improvements con- 
sisted mainly in the use of a new spark-gap having 
a great damping, and in increasing the extent of the 
antenna and of the amount of energy radiated. 
Arguing from a comparison of the signals received 
from Brussels, Norddeich, and Paris, Prof. Wien 
pointed out that there appeared to be difficulties with 
the present spark circuit, and he expressed the wish 
that tests should be made with the continuous-wave 
system. The commission decided that a small high- 
frequency alternator should be acquired, considering 
that larger machines are not developed sufficiently 
yet to warrant the expense. 
Reports were read on the photographic registration 
of signals and other subjects. The reports led to a 
discussion on the strength of the signals received at 
the various receiving stations, and the commission 
expressed the wish that the experimenters should send 
in, with the results of their experiments, the char- 
acteristics of their antenna, and that, whenever pos- 
sible, they should employ photographic registration. 
Mr. Duddell read a paper with regard to the 
methods and instruments to be employed at the 
different stations, and other communications were 
dealt with. 
It was decided to send out from the high- : 
TOK AG - 
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