Pièce 33 - Letter from George Airy

3 pp.

Royal Observatory Greenwich - GA has looked at the account of [John Scott] Russell's Forth tides in the Athenaeum and 'think you will find that Russell's notion of the southern and northern waves exhibiting themselves separately is wholly untenable, both from theory, and from the consideration that they ought to shew themselves as well in the coast tides; but in fact if there are two they become one inseparable tide. The real explanation I have no doubt is in the theory of deep waves in shallow canals'. GA gives the formula and coefficient (for the rise of tide / depth of channel) showing the height of the water after running over a shallow bottom for a certain distance. GA has looked over WW's tide paper and has a problem with the figures and arrangement of the data given in the tables of Plymouth observations.