SCIENCE AND INDUSTRY. 
In the spring of 1917, when the United States had decided to enter 
the war on the side of the Allies, proposals were made to the Navy 
and Air Board, and to the National Research Council of the United 
States, to co-operate by developing the supplies of helium 
available in the United States. The authorities cited agreed 
to co-operate with vigour in supporting these proposals, and large 
orders were at once placed by them with the Air Reduction Company 
and the Linde Company for plant, equipment, cylinders, &¢. The 
Bureau of Mines also co-operated by taking steps to develop a new type 
of rectifying and purifying machine. By July, 1918, the production of 
helium in moderate quantities was accomplished, and from that time 
forward the possibility of securing large supplies of helium was assured. 
The advances actually made at the time the armistice was signed 
warrants the opinion that by the present time, had the work projected 
been completed, supplies of helium at the rate of 2,000,000 cubic feet 
a month would have been produced within the Empire and the United 
States at a low cost, helium-filled aircraft would have been in service, 
and great progress would have been made in exploiting the technical and 
scientific uses of this gas. 
Before the war a proposal to utilize helium as a filling for airships 
would have been viewed, even by most scientists, as impossible, but, 
thanks to the enterprise, enthusiasm, and initiative of the Navy, backed 
by imagination, a suggestion—at one time considered to be chimerical— 
has to-day become a realization. 
3. Drrenstve Measures. 
From time to time publicity has been given to the steps taken by the 
British Navy, in co-operation with the Navy of the United States of 
America, to close to the passage of submarines such sea areas as the 
northern portion of the North Sea and the Straits of Dover. 
At the time of the signing of the armistice, this stupendous task 
was well advanced. The material used consisted largely of ordinary 
contact mines, which were used in vast numbers, and at the expenditure 
of enormous labour and capital. 
_ It can be stated now, however, that, concurrently with the installa- 
tion of this system of defence, other systems of dealing with these and 
similar areas were worked out, which involved the use of more subtle 
mechanisms in quantities which were vastly smaller in amount. 
_ To-day it is scientifically possible and practicable, with a compara- 
tively small amount of material, to close effectively to the passage of 
submarines by either automatic mechanisms or by controlled ones, such 
sea areas as the Bristol Channel, the water stretch between the Mull of 
Cantyre and the north coast of Ireland, the Straits of Dover, the sea 
area between Belgium and Denmark, the Cattegat and Skager Rack, 
and the greater portion of the North Sea between the Orkneys and 
Norway. 
This will serve to show you, in a measure, the part science has been 
able to play during the war. Had the knowledge we now possess been 
available at the opening of the war, we should have been spared much 
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