AIRE AND CALDER. DUN. 99 



AIRE AND CALDER. 



At Castleford the Aire, reinforced by the Calder, enters the 

 magnesian limestone range, and continues in it through the 

 smoke of innumerable kilns to Knottingley, giving easy access 

 to the valuable building-stone and limestone of Weldon, Brother- 

 ton and Knottingley, and the gypsum of Fairburn. It is a me- 

 lancholy description of Ferrybridge, to say that it was formerly 

 on the great road from York to London. The course of the river 

 is now through low lands to Snaith, Rawcliff and Airmin, where 

 it joins the Ouse. 



Before quitting the valleys of the Aire and Calder, it seems 

 worth recalling to memory, that the flat meadows which margin 

 these streams, through a great part of their course, are formed 

 by gradual deposits from freshwater inundations and the tide, 

 laid upon a more rugged and uneven basis, which was an old 

 arm of the sea. In the vale of Calder, for some distance above 

 Altofts, glacial drift is found below the alluvial sediment. In 

 the same valley, at Stanley, this alluvial sediment at 16 feet in 

 depth contained a British canoe scooped out of an oak-tree. 

 This deposit by the side of the Aire at Ferrybridge contained 

 coins of Edward I., below these, oars of an ancient boat, and still 

 lower, a buried forest of hazels, with nuts ; the kernels of the 

 nuts and central parts of the wood petrified in certain spaces of 

 the woody layer. Bones of deer accompanied this curious 

 deposit (see Phil. Mag. 1827). 



The Ouse, now widening and making a large sweep within 

 sight of Howden and its noble church, passes by Hooke to 

 receive the Dun at Goole. 



DUN. 



The DUN, called by Camden Dan and Dane, also, but not 

 properly, named on maps the ' Don/ has a double source ; the 

 same hills giving origin to the Dun and the Little Dun ; they 



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