Plate, figures 1-2 showing line of no tide in ocean and cotidal lines by William Whewell Two figures showing diagrams of the line of no tide in the ocean as well as cotidal lines. Later versions of these diagrams are found at PT/34/1/5. Subject: Hydrography Published in Philosophical Transactions as 'The Bakerian Lecture.—Researches on the tides. Thirteenth series. On the tides of the Pacific, and on the diurnal inequality'. Written by Whewell in Trinity Lodge, Cambridge. Received by the Royal Society on 11 November 1847. Read 16 December 1847. 8 November 1847