The tethered balloon, which has been in Paris' Andre Citroen Park for 25 years, was slowly deflated over three days in order to change it. As with the Olympic cauldron, the recovered helium will be recycled. "It's important to preserve this rare and expensive resource," says François-Xavier Onfray, Technical Director of Aerophile, a French company that manufactures balloons delivered all over the world. IMAGES AND SOUNDBITES