Mersey may be described as the most modern of our rivers. There was a time, in fact--and that not measured by geological computation--when, so far as knowledge of it went, the Mersey could hardly be said to be in existence. Even the great estuary where a world's argosies now assemble escaped the attention of the Romans, and we come down to the beginning of the eleventh century before we find the Mersey named in any record. It is mentioned for the first time in a deed of the reign of Ethelred, and there it figures less as a river than as a boundary mark concerning a grant of some lands "between Maersae and Ribbel." It has been said also of the Mersey that it got its name from the fact that it formed the northern limit of the kingdom of Mercia. Another derivation, and not an altogether unlikely one, when considered along with the chief seat on its banks and the open channel beyond, is that in "Mersey" we have the Celtic word "Marusia," signifying quiet or sluggish water. A more curious derivation, and one lending itself to the belief that in the early history of our country the character and identity of the Mersey were very different from what they are to-day, is that the word is from the Anglo-Saxon "Meres-ig," or "Sea-Island." It is known that what is now the Wirral Peninsula, forming the western boundary of the estuary of the Mersey, was at one time cut off from the mainland by the sea. It is known also that the Dee flowed over into the Mersey; and as the two rivers must then have appeared as one, with a common mouth, it is easily seen how in the long ago the Mersey would escape recognition altogether. But the river that was to minister to the greatness of Lancashire, and through Lancashire to aid so materially in the development of industrial Britain, was, of course, no sudden creation. It may have been for ages nothing but quiet or dead water, but Nature in her slow and sure way was all the while working in its favour. For centuries, vessels, as they sailed up and down the west coast, passed by the Mersey, and found their way instead up the Dee to Chester, or up the Ribble to Preston, and occasionally up the Lune to Lancaster. But, even as they did so, these streams were gradually becoming less navigable. A strong tidal flow raised sand barriers at their entrances, and for some considerable distance upwards, that meant danger to shipping. The same cause gave the Mersey its opportunity and its individuality; and once the bar at its mouth was crossed, there were found not only capacious and safe anchorage, but possibilities for commercial enterprise that have gone on increasing from the moment at which men began to take advantage of them. [Illustration: THE MERSEY.]