I'm watching a NOVA episode about World War I Zeppelins. The Germans used collagen to construct the bags that held the hydrogen. They got it from cow guts. The small sections were joined simply by getting them wet and then overlapping the edges. The seams were gas tight and as strong as the material itself. It took 250,000 cows to make a zeppelin. Unreal. That's a lot of cows!

 

Holy Hindenburg ...It is a wonder that they did not explode with the methane fumes in the factories as opposed to the burning hydrogen .

 

According to the show, for a while during the war making sausages was illegal because they needed all of the intestines for airships.

 

Dang, I forgot that was on. I was going to record it.

 

Try On Demand. With no commercials, PBS is all over that. Or just watch it online: NOVA | Zeppelin Terror Attack