This notice is occasioned by a passage in the fifth volume of the Transactions of the British Association, page 251, in which Professor Challis claims for himself the merit of having been the first who deduced from mechanical principles the anomalous emergence of a floating body from a fluid at high velocities, and where he adduces Mr Russell's experiments in support of the method of reasoning he has there adopted. Previous to the publication of his paper, Mr Russell had given the theoretical explanation of the phenomenon, and had also adduced experiments in support of that explanation at the meeting of the British Association in Edinburgh.