18 PKOPERTIES OF WOOD. 



following tins plan ; his transparent wood-sections afford 

 splendid material for studying the anatomical structure of 

 wood ; li. liartig * gives plates of somewhat enlarged sec- 

 tions, and his pamphlet is belter written and more practical 

 than Nordlinger's book. Dr. Moller t also has published an 

 excellent pamphlet with good plates on the structure of wood. 

 The transverse section is, however, but rarely exposed in 

 utilized wood, which usually occurs in longitudinal sections 

 cut more or less parallel to the axis of the tree. These 

 sections also show the wood-texture best ; foresters should 

 recognize European and the more important foreign woods, 

 not only by transverse sections, but also by the more important 

 longitudinal sections. The radial or silver-grain section, 

 more or less in the plane of the medullary rays and radially 

 inclined to the pith (Fig. 7, S), show's the vessels as finely 

 carved grooves or lines, of various lengths, the medullary rays 

 along parts of their length perpendicular to the annual rings, 

 and in their height or breadth ; the annual rings are less 

 sharply defined than in the transverse section, but still 

 sufficiently distinct. The other longitudinal section is more 

 or less tangential to an annual ring, it is termed the tan- 

 gential section (Fig. 7, F) : on it the vessels appear as grooves 

 of various length, the longer, the nearer is the cut to the 

 true tangent ; the medullary rays (Figs. 7 and 8, F, c) are cut 

 transversely and show their height and thickness ; the 

 annual rings appear as wavy bands that greatly improve the 

 appearance of the wood-texture, so that economically this 

 section is very important. Burkart (Brunn, 1881) published 

 a collection of forty wood-species, prepared by Podany in 

 Vienna; each species was in a frame with three compartments, 

 one for each of the above sections. By this excellent method, 

 a work of exceptional utility was produced, but unfortunately 

 the edition is exhausted. A similar procedure was followed 

 in America by Pi. B. Hough, of Louville, New York, which 

 sho\vs the American woods in three characteristic sections, 



* It. Mai-tig, " Die Qnterscheidunggmerkmale der wichtigereu in Duiitsdilaud 

 wachseiiden Jlol/ur," 4 Anil, IS*S. The iJnl edition of llarlig's book is trans- 

 Lited by Somerville. Douglas, Edinburgh, 1890. 



.1. Moller, "Die lloMnf]'-: dr* Tix-hK-rs u. Dreehfllegewerbew.' 1 I. Das 



llol/.. 



