Pascal proposed three questions relating to the center of gravity, area and volume of the cycloid, with the winner or winners to receive prizes of 20 and 40 Spanish doubloons. Pascal, Gilles de Roberval and Pierre de Carcavi were the judges, and neither of the two submissions (by John Wallis and Antoine de Lalouvère) were judged to be adequate. While the contest was ongoing, Christopher Wren sent Pascal a proposal for a proof of the rectification of the cycloid; Roberval claimed promptly that he had known of the proof for years. Wallis published Wren's proof (crediting Wren) in Wallis's Tractus Duo, giving Wren priority for the first published proof.
pascal proposed three questions relating to the center of gravity area and volume of the cycloid with the winner or winners to receive prizes of 20 and 40 spanish doubloons pascal gilles de roberval and pierre de carcavi were the judges and neither of the two submissions (by john wallis and antoine de lalouvère) were judged to be adequate while the contest was ongoing christopher wren sent pascal a proposal for a proof of the rectification of the cycloid; roberval claimed promptly that he had known of the proof for years wallis published wren's proof (crediting wren) in wallis's tractus duo giving wren priority for the first published proof