2o6 THE EVOLUTION OF DERBYSHIRE SCENERY. 



Take the case of the springs which supply the Fountain Baths at 

 Matlock Bath. Here many thousands of gallons pass through 

 the baths and run into the river every day, the supply being 

 scarcely affected by a long spell of dry weather. Sometimes the 

 water of a river will in this way find its way to an outlet at a lower 

 level, leaving its old channel high and dry. As the volume of 

 water poured into the subterranean conduit increases, the work 

 of dissolution proceeds apace, and where the water enters, a 

 " swallow hole," sometimes deep, and with precipitous sides, is 

 produced, and in its further journey " eats out " in the course of 

 its wanderings huge chambers, wliich constitute the " natural 

 wonder " of a future age. While the erosive action of the water 

 is mainly chemical, it must not be forgotten that, especially in 

 periods of heavy rain, it is supplemented by the mechanical 

 action of suspended particles. It was once the writer's good 

 fortune (in the company of Messrs. Arnold-Bemrose and John 

 Ward) to explore a portion of such an underground watercourse, 

 into which, by accident, the workings of a lead mine (the 

 Bagshawe Cavern, at Bradwell, near Castleton) had penetrated. 

 Here and there upon the floor lay huge tabular masses of lime- 

 stone which had been detached from the roof, and in other places 

 the floor was thickly covered with a sandy deposit, brought down 

 during storms by the surface waters. The action of these sandy 

 particles, carried by a rapid torrent in a tortuous underground 

 channel, cannot be overlooked. At the time of our visit there 

 iiad been a long dry season, during part of which this portion of 

 the underground channel had been temporarily deserted, alihougli 

 the rush of waters could be heard in the neighbourhood. During 

 times of storm even large fragments of rock may be taken up in 

 the current and used as battering-rams for the destruction of 

 opposing obstacles, and Professor McKenny Hughes* has well 

 described from personal observation the progress and action of a 

 sudden and violent storm upon the cave and slopes of Ingle- 

 borough — a somewhat similar district. Here the action of 



* "On Caves." Trans. Victoria Institute, 1887. 



