CORRESPONDENCE. THE TRAINING OF RIVERS AND ESTUARIES
Minutes of the Proceedings of the Institution of Civil Engineers
Proceedings.] DISCUSSION ON TRAINING OF RIVERS. 103 not extend more than 2 miles below the neck, the rise of tide being Mr. Partiot. only 2 feet; whereas depths of over 33 feet were found up to San Juan del Norte, 8 miles above the neck. On the Mersey, where the river was small, and the tides had a large range, the channels of the upper estuary were short, whilst the outlet-channel had great depths for over 9 miles. Much time had been devoted by Mr. Vernon-Harcourt to smallscale models, with
... ale models, with which he had carried out experiments in relation to the Mersey and the Seine. The model experiments undertaken a t Rouen had furnished results which were only imperfectly known ; but nevertheless he could say that those which had been ascertained had varied considerably, according to the duration of the experiment, and the manner in which new sand was placed in the model. He thought that Mr. Vernon-Harcourt would have obtained different results with his model if he had continued each of his experiments for a longer period; and he would, therefore, urge the importance of the precautions necessary, in using small-scale models, to obtain useful results.