(7)
The second point was that if the Admiralty were immediately to announce the destruction of an enemy submarine the enemy "would know without waiting that a relief for that particular boat was required and they would at once despatch another submarine, if available, to operate against our ships. I would rather leave them to imagine that they are there when they are not. As it is the enemy cannot know for some time the exact number of their submarines that have been operating at any particular moment."
BRITISH ENGAGEMENTS WITH U BOATS.
A further and the strongest argument was that the Admiralty did not know whether an enemy submarine had or had not for certain and in fact been destroyed. "All we know is that from day to day and from week to week reports come to us of engagements with enemy submarines, and it follows of necessity that the results range from the certain, through the probable down to the possible, and improbable. In the case of the submarine it is only absolutely certain when you have taken prisoners. After all, the submarine is operating mainly under the water. A submarine dives, and very often someone thinks that it has sunk. A submarine sometimes dives when it is wounded—no doubt never to come up again, but you cannot tell. I should be sorry to mislead the country by giving them only what you could call, under the circumstances I have mentioned, 'certainties.' I know it would be misleading. On the other hand if I gave them probabilities it might be equally misleading. The degrees of evidence in relation to the sinking of every submarine, or the report of the sinking of every submarine, vary to the most enormous extent."
Sir Edward declared that he held in his hand brief accounts of some forty encounters which the British Fleet had with the submarine since February 1. "Recollect what they are doing, and how they are working. The fact that we have got into grips with them forty times in eighteen days is an enormous achievement." He gave a few illustrations to show the difficulty of establishing the large majority of cases definite conclusions, taking his illustrations in the order of probability.
AN ABSOLUTE CASE.
The first illustration presented no difficulty whatsoever:
"A few days ago one of our destroyers attacked an enemy submarine. They hit the submarine, and, as events showed, killed the captain. The submarine dived. If she had remained below it would have been au uncertainty, but as a matter of fact she was injured only so much as that she was compelled, but able, to come to the surface. She was captured. and her officers and men were all taken prisoners. That is an absolute case. But look how different it might have been if the submarine had been so injured that she was unable to come to the surface and had remained at the bottom of the sea."
His second illustration was that of a report received from a transport that she had struck an enemy submarine and was
