CONTENT

This web page n-cruickshank1013-whatisgood.blogspot.com states the following, "50 years, 50 giant leaps! 1The hand-held vacuum cleaner." We saw that the webpage said " Before 1971, the average weight of breathing apparatus was more than 30 pounds." It also said " Carrying the extra weight was so physically gruelling that some firefighters opted to attack flames without any equipment. However, engineers at Nasa adapted the life-support systems used in spacesuits for use by emergency services. Four years later, experts had designed apparatus that weighed a third less and offered better fit."