Settle down, everybody. Ready? Well, 'Once upon a time, there was a king…' A teacher takes her young children through their gas mask drill. Gas masks were issued to all children as a precaution ...

In the lead-up to World War II there ... poisonous gas, so by 1938 the government had issued respirators to every man, woman and child in the nation. More than 40 million gas masks were issued.