526 



IMBEDDING OF OEGANIC EEMAINS 



[Ch. XLVI 



sea since the flood ! A wooden apparatus that accompanied 

 the boat in its progress through the deep, consisting chiefly 

 of a piece of thick deal, about fifteen inches square, happened 

 to fall overboard, and though it originally consisted of the 

 lightest fir, sank in the water like a stone. The boat was 

 rendered useless; even the wood of which it was built, on 

 being offered to the cook for fuel, was tried and rejected as 



incombustible 



elm 



became impre 



ometimes 6,000 feet, 



immer 



•' ^w-^^^ ^^ AA^tA; urn 



The effect of this impregnation was to increase the dimen- 

 sions as well as the specific gravity of the wood, every solid 

 inch having increased one-twentieth in size and twenty-one 



t 



DrifUwood of 



When timber 



down by a river, it is often arrested by lakes ; and, becoming 

 water-logged, it may sink and be imbedded in lacnstrine 



forming: ; sometimes 



on till it readies tbe sea. In the 



Mackenzie 



North 



an example of vast accumulations of vegetable matter now in 

 progress under both these circumstances. 



In Slave Lake in particular, which is 200 miles long, the 

 quantity of drift- timber brought down annually is enormous. 

 'As the trees,' says Dr. Richardson, 'retain their roots, 

 which are often loaded with earth and stones, they readily 

 sink, especially when water-soaked j and accumulating in the 



•m 



small 



soon as it appears above water, and their fibrous roots serve 



mly 



Sections of these islands 



m 



the diversity of appearances they present, according to their 

 different ages. The trunks of the trees gradually decay 

 until they are converted into a blackish-brown substance 



■1 



\ 



* Accoiir.t of the Arctic Eegions, toI. ii. p. 193. 



t Ibid. 1^. 202. 



