PERPETUAL MOTION
“Excuse me, but do you mind keeping your dog indoors at night till the war is over?”
“Why?” said the surprised dog-owner to the stranger.
“Well, your dog’s barking sounds just like a ‘special’ boy shouting in the distance. My wife’s got two brothers at the front, and every time she hears your dog she sends me racing down to get the ‘special,’ and says I’ve been too stupid to catch the boy.”