????? ? ??? ??? ?????? ??? ??? ? ???, ??? ????? ?? ?? ??? ???? ??? ???? ??? ??? ??? ??? ? ????.René Descartes's sketch of how Principal and secondary rainbows are fashioned, Discours de la Méthode, 1637. Descartes' 1637 treatise, Discourse on Process (Discours de la Méthode), additional Innovative this rationalization. Knowing that the measureme