ORGANIC STRUCTURE. Ill 



materially affect the properties of the timber pro* 

 duced upon them. 



For several years past there has been great com- 

 plaint of the deterioration of oak timber, especially 

 in the dockyards. Compared with oak beams in 

 ancient buildings, that of modern growth is absolutely 

 worthless, falling a prey to dry rot before the ships 

 built of it have been launched from the stocks ! Its 

 inferiority has been attributed to want of age, to arti- 

 ficial cultivation, to want of seasoning, to the wrong 

 variety being planted, and to the more general pre- 

 valence of dry rot. Whether any of these circum- 

 stances may have been the cause of the deterioration, 

 is not clearly ascertained ; but it is more than pro- 

 bable, that the quality of the soil whence the trees 

 have been felled, if duly investigated, would show 

 the true reason of the deterioration. 



The layers of many years form aggregately the 

 body of timber which, in all its stages, has an obvious 

 longitudinal arrangement ; splitting most easily from 

 top to bottom, and in right lines through the pith ; 

 and also readily in the direction of the sides of the 

 layers, which separate from each other with ease. 

 These concentric layers are only attached to each 

 other by fine cellular matter, but without any inter- 

 junction of their fibres ; the diverging partitions, 

 which proceed in right lines from the first layer 

 to nearly the outside of the bark, appear to be the 

 connecting ties which keep the whole together. In 



