128 PROPERTIES OF WOOD. 



obliquely inclined stems was in 1896 termed red-wood by 

 Mer. Schwarz earlier than this had termed extremely hard 

 wood " Druckholz," tension-wood. The name "red-wood" 

 is unsatisfactory, as this abnormity is not due to colouring 

 matter but to the great accumulation of lignin. Abnormally 

 thick cell-walls are red for the same reason that ice is 

 blue. 



[H. J. Elwes in a paper read before the Surveyors' Institu- 

 tion in 1904,* drew attention to a form of oakwood known as 

 "Brown Oak," which is extremely valuable and is used for the 

 internal decoration of houses and for heavy furniture. The 

 sapwood of these oaks is normal in colour, but the dark 

 heartwood occurs throughout the stem, and branches when- 

 ever the latter are sufficiently thick to contain heartwood. A 

 group of young oaks were felled in Essex, not more than 

 12 to 18 inches in diameter, all perfectly sound and the 

 heartwood of a rich brown colour. Woodmen in Essex con- 

 sider that trees, which retain their leaves longest in winter, 

 have " red wood," the local name for brown oak. Some of 

 the most valuable brown oaks grew in Eockingham Park, in 

 Northamptonshire, and the junction of oolitic rock bearing 

 iron-stone bands, with lias clay, appears to be favourable for 

 this variety. Often brown oak is due to internal decay in the 

 bole of a tree, but sometimes it is quite sound. Owing 

 to the great beauty and value of brown oak, it is advisable 

 that experiments should be made to determine, whether this 

 quality is hereditary, and what conditions of soil and locality 

 favour it. Apparently it is not known on the Continent. 



The stump-wood of Erica arborea, called briar-wood from 

 the French bruyere, forms large masses of wood that is heavy 

 and with contorted fibres but even-grained, of a rich reddish 

 brown colour and easily turned and carved. It is the best of 

 wood for pipes. Tr.] 



(b) Abnormal Direction of Fibres. 



Every wound disturbs the course of the fibres round the 

 occluding tissues ; they are curved until several years after 



CJ\ Chapter on oak in the "Trees of Great Britain and Ireland," by 

 Klwes and Henry, 19U7. 



