Afterward I grew accustomed to the Channel crossing.  I made it four times.  It was necessary for me to cross twice after the eighteenth of February, when the blockade began.  On board the fated Arabic, later sunk by a German submarine, I ran the blockade again to return to America.  It was never an enjoyable thing to brave submarine attack, but one develops a sort of philosophy.  It is the same with being under fire.  The first shell makes you jump.  The second you speak of, commenting with elaborate carelessness on where it fell.  This is a gain over shell number one, when you cannot speak to save your life.  The third shell you ignore, and the fourth you forget about—­if you can.

Seeing me alone the captain asked me to the canvas shelter of the bridge.  I proceeded to voice my protest at our change of destination.  He apologised, but we continued to Boulogne.

“What does a periscope look like?” I asked.  “I mean, of course, from this boat?”

“Depends on how much of it is showing.  Sometimes it’s only about the size of one of those gulls.  It’s hard to tell the difference.”

I rather suspect that captain now.  There were many gulls sitting on the water.  I had been looking for something like a hitching post sticking up out of the water.  Now my last vestige of pleasure and confidence was gone.  I went almost mad trying to watch all the gulls at once.

“What will you do if you see a submarine?’

“Run it down,” said the captain calmly.  “That’s the only chance we’ve got.  That is, if we see the boat itself.  These little Channel steamers make about twenty-six knots, and the submarine, submerged, only about half of that.  Sixteen is the best they can do on the surface.  Run them down and sink them, that’s my motto.”

“What about a torpedo?”

“We can see them coming.  It will be hard to torpedo this boat—­she goes too fast.”

Then and there he explained to me the snowy wake of the torpedo, a white path across the water; the mechanism by which it is kept true to its course; the detonator that explodes it.  From nervousness I shifted to enthusiasm.  I wanted to see the white wake.  I wanted to see the Channel boat dodge it.  My sporting blood was up.  I was willing to take a chance.  I felt that if there was a difficulty this man would escape it.  I turned and looked back at the khaki-coloured figures on the deck below.

Taking a chance!  They were all taking a chance.  And there was one, an officer, with an empty right sleeve.  And suddenly what for an enthusiastic moment, in that bracing sea air, had seemed a game, became the thing that it is, not a game, but a deadly and cruel war.  I never grew accustomed to the tragedy of the empty sleeve.  And as if to accentuate this thing toward which I was moving so swiftly, the British Red Cross ship, from Boulogne to Folkstone, came in sight, hurrying over with her wounded, a great white boat, garnering daily her harvest of wounded and taking them “home.”