The Manchester Ship Canal Works. 37 



that at one time there existed a Lancashire Dead Sea. Where 

 the triassic rocks were being deposited the scene presented to 

 the imagination was a great salt lake, in the midst of an arid 

 desert, with a scant and stinted vegetation. Little in the way 

 of living creatures was to be seen ; but the waters were at times 

 frequented by strange amphibious monsters, who crawled across 

 the sand banks and left queer footprints, to be preserved to our 

 days. It had been a source of surprise and disappointment to 

 the geologists of Manchester that in the magnificent sections 

 opened up to their study, so few relics of man, of his handiwork, 

 or of the extinct animals who disputed with him the sovereignty 

 of the woods and fields, had been brought to light. One reason 

 why so little had been found was that the Irwell valley, below 

 Manchester, is a very wide one, and the windings of the river, 

 though very complicated, yet are in the main confined to the 

 central part of the valley, where only the more recent of the 

 river deposits are accumulated, the older ones occurring as 

 terraces or plateaux near to the boundary hills, and consequently 

 away from the line of the ship canal. 



In concluding, the lecturer remarked that, as had been hap- 

 pily expressed by an eminent living citizen of Manchester, Mr. 

 Alderman Bailey — " There never will be a better opportunity 

 than the present for the scientific and archaeological student 

 to read the story of the rocks in the cuttings of the Ship Canal. 

 The gradual formation of the stone, the ancient strands of sand, 

 the old lagoons formed on the sites of the prehistoric forests, 

 the fossils, the boulder clay, all in view, are rich with suggestive 

 matter to the students of the knowledge of causes. Nature 

 sometimes makes rock in a clumsy fashion ; — the mountain 

 stream picks up and holds in solution sulphate and carbonate of 

 lime and magnesia, silica, and other mineral particles, and 

 deposits these among the sand in the valley below, sometimes 

 in wrong proportions, and often in the wrong place. In the 

 crucible of time the ingredients mix together and harden, and 

 become building stone, which is used by man. We see nearly 

 the same process going on in the way that artificial stone is 



