World War I: Something you did not know

I've been looking for different inventions invented in the First World War, and that most impressed me was the tea bags. I did not know that tea bags were invented in the First World War, I thought it was an invention of the Japanese for thousands of years ago. Tea bags was an invention of the Americans but German just copied the idea to sell ir in the war and make some money. It was an American tea merchant who, in 1908, started sending tea in small bags to his customers. They were design by accident, surely someone accidentally dropped a bag in the water, taste it and says: "what a great idea!". But a German company, Teekanne, did copy the idea in the war, and developed it, supplying troops with tea in similar cotton bags. They called them "tea bombs". There were not invented to solve any problem in the war, but today its a very useful think.