About giving helium to Germans for the Hindenburg. I should not have said fighter planes with rockets. We did have one plane with a cannon. But we had planes with six and eight
heavy calibre machineguns that could easily have riddled a Zeppelin. And the Germans would have used Zeppelins with hydrogen if they had been useful in war. I can't think of any other military use of helium.
Incidentally "riddle" is an interesting word. When I worked in a foundry, I was surprised to hear the moulders use the word "riddle" for what I would have called a sieve to sift the sand into the moulds.