Summary The balloon mania between 1783 and 1785 put an extraordinary strain on the Paris Academy of Sciences, threatening its status as the highest tribunal of European science. Faced with repeated royal directives and public frenzy, the Academy manoeuvred carefully to steer the research toward the hydrogen balloon and thereby to maintain its scientific superiority. Antoine-Laurent Lavoisier seized this moment when the promise of ‘the empire of airs’ brought science to the centre of public attention to push his theoretical reform (...) for chemistry. He utilized the established protocol of the Academy and the resources of the Republic of Letters to broadly publicize his first decomposition of water in April 1784. Once he attained the publicity and the balloon fever began to cool, he staged a much more elaborate experiment for the experts in February 1785. Although this second, large-scale experiment cost much expense and effort, Lavoisier never published a full account. The differential care given to the two experiments can only be understood in their divergent rhetorical contexts. The written accounts in 1784 addressed the court of public opinion, while the exclusive performance in 1785 aimed at the court of experts to inaugurate the collaborative phase of the Chemical Revolution. (shrink)