For a moment one is conscious of a slight pressure in the ears; we are shut up from outside and all is still, but there is no real silence; only a change of sound.

Then comes the command:

"Open the submerging valves!"

"Flood!"

What now follows is so strangely impressive that one could never forget it, once having experienced it. The submerging valves are quickly opened, and with a hiss the compressed air rushes out of the tanks. A gigantic volume of air rises, with such an unearthly snorting and blowing that the pressure in one's ears becomes almost painful. Then the noise becomes more even, and is followed by a loud humming and whistling, and all the high notes of the machinery in the engine-room join together and produce a confusion of sounds.

It is like the strains of some mad, diabolical music that, after the dull, heavy hammering of . . . Read More