Paper, 'On the maximum discharge through a pipe of circular section when the effective head is due only to the pipe’s inclination' by Henry Hennessy Hennessy writes: 'In the paper on “Hydraulic Problems on the Cross-sections of Pipes and Channels” [see PP/12/2], it was shown that the greatest hydraulic mean depth was that for a channel formed by a segment of a circle, and bounded by an arc of 257° 27'. It is easy to find by a similar process the wetted perimeter of a circular pipe corresponding to the maximum discharge when the velocity of the liquid is due only to the inclination of the pipe.' Annotations in pencil and ink. Subject: Hydraulics / Engineering Received 15 November 1888. Read 20 December 1888. A version of this paper was published in volume 45 of the Proceedings of the Royal Society as 'On the maximum discharge through a pipe of circular section when the effective head is due only to the pipe’s inclination'. 1888