ELASTICITY OF CONIFEROUS WOOD. 87 



course, is influenced to some extent by climate and environment. 

 The best even-grained coniferous wood has equal annual rings with 

 narrow summer zones and fine medullary rays. The most elastic 

 European coniferous woods are the Yew, Larch, Spruce Fir, Scots 

 Pine and Silver Fir ;* and among the most elastic American species 

 are the Western Larch, southern Pitch Pine, Spruce Pine, Noble Fir, 

 Prince Albert's Fir, Douglas Fir and Lawson's Cypress.f 



The elasticity of the wood of the Yew was observed centuries ago 

 which led to its being employed in making bows for archery. The 

 elasticity of the coniferous 'woods mentioned above materially enhances 

 their utility in the various purposes of carpentry to which they are 

 applied. The property is, however, most decisive 1 y demonstrated by the 

 readiness with which molecules of the wood receive and transmit the 

 vibrations of sound ; this is especially the case in the Fir and Pine 

 tribe. The late Dr. Tyndall, in giving the results obtained by the 

 experiments of Wertheim and Chevandier to determine the velocity of 

 sound through different kinds of wood, showed that the velocity along 

 the fibre of Fir wood is fourteen times the velocity in air ; in other 

 words, that whereas sound travels under ordinary circumstances through air 

 whose temperature is 60 e Fahr. at the rate of 1,120 feet per second, it 

 travels through Fir wood at the rate of 15,218 feet in the same period 

 of time. Also along the fibre of Pine wood it is ten times the 

 velocity in air. He also further proved the elasticity of Fir wood 

 by a beautiful experiment, by which musical sounds generated in one 

 apartment of a building were transmitted through a long deal rod 

 and perfectly reproduced in another. J The high degree of elasticity in 

 the molecular structure of Fir and Pine wood renders it a suitable 

 material for the construction of certain parts of several musical instru- 

 ments, as the violin, piano, etc., for which it is much employed. 

 The DURABILITY of coniferous wood is dependent in some measure 

 on its specific gravity, or the ratio which the weight of a certain 

 volume of wood bears to that of an equal volume of water, but no 

 definite law can be formulated from the relationship. The specific 

 gravity of the wood may be expressed with numerical precision, but 

 sufficient data are not forthcoming to co-ordinate with it the duration 

 of time which wood will last in a sound and useful condition under 

 stated circumstances, or when out of the reach of destructive agencies. 

 The most durable European coniferous woods available for utilisation 

 are the Yew, Larch, Spruce Fir and Scots Pine, all of a relatively 

 high specific gravity ; but more durable than either of them is the 

 wood of the common Cypress (Oupressus tempervirens) which no 

 longer exists in sufficient quantity for any general economic use. 

 Some of the most durable and in some respects the most valuable 

 of the American coniferous woods belong to the Cypress tribe, 

 the specific gravity of most of which is relatively high. The 



* Schlicli, Manual of Forestry, Vol. V. p. 44. 



t Jesup Collection of Woods of the United States, by C. S. Sargent. 

 J Lectures on Sound, pp. 41, 80. 



