IN NORTH STAFFORDSHIRE. 153 



formation attains a greater elevation, giving rise (in con- 

 junction with the mountain limestone) to beautiful scenery 

 of rock and water, there is a marked absence of waterfalls. 

 Our worthy friend and admirable local historian and natu- 

 ralist, Mr. Garner, speaks, I observe, of the small rivers 

 in the valleys in the northern parts of Staffordshire, as 

 "forming occasionally fine cascades over the grit rocks." 

 I am confident, nevertheless, that he will not regard my 

 statement as inconsistent with his record of actual facts. 

 But what part do the trap rocks in Wales play in the 

 production of waterfalls ? The mudstone rocks and grits 

 of Merionethshire and Carnarvonshire are interlaced with 

 stratified porphyry, and these hard bands stand up like 

 artificial walls across the beds of rivers and streams. In 

 vain the water has waged a perpetual warfare against its 

 antagonist. Its ambition is doomed to incur a fall ! It is 

 now a quarter of a century since I was first struck with 

 this natural history of the waterfalls of North Wales. 

 After an instructive visit with Professor Sedgwick in the 

 summer of 1846, I returned in the autumn to work out 

 the succession of beds between Bala and Snowdon, and I 

 could now, without reference to sections or maps, point 

 out numerous illustrations of the connection existing between 

 waterfalls and the lines of trap rocks. I shall, however, 

 now only refer to the fall of the Conwy, before mentioned. 

 There a basaltic dyke has stopped the scooping out process 

 of the river, and caused the fall. I invite any members 

 of this society who may visit Llandudno in the coming 

 summer to test this for themselves. In another way, 

 although less direct, the existence of beds or walls of 

 hard rock tends to produce waterfalls. These falls, as we 

 have seen, are the result of the incessant action of water 

 for countless ages. Constant action denotes a constant 

 supply of water. This is only effected by natural reservoirs 



