Canadian Forestry Journal, May, ip20. 



21' 



Phcto, Courtesy Mr. E. E. Lemieux. 

 YOUNG LIVE CANADIAN BEAVER. 



that it cannot be considered as an im- 

 portant species for this purpose. 



White pine, western white pine and 

 sugar pine possess certain quaHties 

 which enable their use for some pur- 

 poses, especially in ply-wood. 



Where for Black Walnut? 



The amount of hardwood entering- 

 inti I the construction of an aeroplane 

 is comparatively small, and there will 

 l)robaljly he no difficulty in meeting- 

 any demand tnr this industry. The 

 one exception in i)erhaps black wal- 

 nut, which is considered the l)est 

 pro])eller stock grown in North Am- 

 erica. Estimates of the total stand 

 are \-cry unsatisfactory. l)Ut the best 

 available tij'.urc^ show a probable 

 stand of 850 million feet in the United 

 States, including all trees over eight 

 inches in diameter. 'I"lu' anioimt over 



:6 inches which will produce aero- 

 plane material must, therefore, be 

 very small. From 1014-1917 tlie cut 

 was between 75 and go million feet 

 annually, but it was greatly increased 

 during 191 S. Future cuts will be con- 

 sideralily below these figures. Exten- 

 sive experiments have been conduct- 

 ed in splicing, lamination and ply- 

 wood construction. Tt w-as found 

 that wing beams can be built up so 

 that they will havf ecpial strength 

 and stiffness to solid wood. This 

 makes it possible to use inferior 

 woods when protected l\v layers of 

 stronger wt>ods and also short clear 

 pieces, which would otherwise be 

 discarded, and effects a consitlerable 

 saving in the actual amoimt of wood 

 used. The cost of construction is 

 hiidier. however, than when stdid 

 wood is used. :ind it is difficult to se- 

 cure the same uniformitv. 



