114 Proceed? tigs of I he British Association. 



the Leasow Lighthouse, affording strong evidence that a burying-ground 

 had formerly existed there, and a similar cemetery is discernible at 

 Formby. This kghthouse stands in place of another, which was nearer 

 to the sea by more than half a mile — a site which, at the time of its erec- 

 tion, seemed to have been firm, dry land, but was rendered useless by 

 the encroachments of the water, which continued to increase. It was 

 not until the sea had broken down the ridge of sand which had formed 

 its boundary, that a strong embankment was made,'extending a mile and 

 a quarter in front of the present lighthouse. The sand banks in this 

 estuary are tossed to and fro by the force of the winds and tides, and are 

 constantly changing their shapes and elevations, and, having no escape, 

 they remain pent up in the bay. In 1687, an excellent channel existed 

 opposite to Formby Point, its depth from three to ten fathoms ; but, not 

 being marked by buoys, the Rock Channel was at that time the entrance 

 in common use, though dry at low water. It has since become deeper, 

 and thus a change has taken place upon the Hyle Sand Bank. A ridge, 

 running along the middle of this bank, has been cut through by a chan- 

 nel having forced itself in a northerly direction, from Helbre island 

 towards the Light Ship. The channel described by Capt. Denham at the 

 Dublin Meeting is now useless, although used for some time with advan- 

 tage ; but it runs perpendicular to the course of the tide, which accounts 

 for its present state. Fears have also been entertained, that the other 

 channel, called the Horse Channel, was filling up. Lately, a diagonal 

 channel has been formed, by aiding the ebb current of the tide in its na- 

 tural diagonal course, between Lancashire and Cheshire. This was done 

 by dredging, by means of a double-toothed harrow, twelve feet across, 

 dragged backwards and forwards by a steamer of 100 horse-power over 

 the intruding banks, the inner part of which was stated to rise forty- 

 three feet higher than the outer or seaward part. An enormous wooden 

 scraper is also used. The matter taken up appears to contain a small 

 portion of peat, and weighs somewhat lighter than the sand found with- 

 in the estuary. This new channel has been proved to answer the pur- 

 poses of navigation beyond original expectation, and the approach to 

 Liverpool is even better than before. 



Mr. De la Beche mentioned, that submerged peat is found along many 

 of the shores of Europe, being evidently the remains of forests that had 

 sunk. These have been covered with sand, and now there are encroach- 

 ments made upon the coasts near them, thus showing two sorts of 

 changes of level. He was averse to any great encroachments being made 

 on the shores of estuaries, as the natural process of scouring by means 

 of the reflux of the tide was diminished. 



