32 D. P. PENH ALLOW ON 



lary niys, liut more generally they arise independently of them. No special longitudinal 

 shear was observed as the result of mechanical stress. 



It would appear from the above two descriptions that there is a very close correspond- 

 ence in the general structural features of 428 and 789, and this harmonizes with their 

 supposed derivation from the same locality. 



No. 316 is a section cut from the centre of an old stringer from a structure two miles 

 east of Spuzzum, and cut near there at an elevation of about 500 feet above sea level. It 

 was in use eleven years, under the influence of a climate like that of Nova Scotia. 



The specimen is very coarse-grained and embraces zones 1, 2, 3 and 4. It cuts hard, 

 the dense and flinty summer wood being thrown out in prominent ridges under the action of 

 the saw. The colour is somewhat conspiicuously red. Both in drying and under the influ- 

 ence of mechanical stress, star and cup shakes are numerously developed, and these again 

 are connected by diagonal fractures. The star shakes are chiefly independent of the medul- 

 lary rays. 



Longitudinal shear under mechanical stress is very prominent in this specimen and 

 exhibits some rather peculiar features, to be referred to later. 



No. 35 is a section taken from a stringer of structure 35, about one mile west of Port 

 Moody, where may be found the heaviest rainfall for the whole province. The timber was 

 cut on the coast, probably at Point Grey, eight miles from Vancouver, and was in use for 

 six and one-half years. 



This specimen is probably of the "fine-grained" variety, although its character is not 

 well defined, and embraces zones 1, 2 and 3. It is distinguished by a much greater uniform- 

 ity of growth-rings than any of the pireceding specimens and the predominance of narrow 

 rings. It cuts evenly though hard, but the summer wood does not appear as flinty as in the 

 previous specimens, and is not thrown out in so prominent a manner by the action of the 

 saw. Shakes are sparingly developed, and chiefly radial, the few very inconspicuous cup 

 shakes being connected with tliein by diagonal fractures. Here, as in the previous eases, 

 the star shakes are independent of the rays. Longitudinal shear is not represented in this 

 specimen. 



No. .'?. A section taken from a stick of timber originally thirty-two inches in diameter, 

 and grown on a hill-side at an elevation of one hundred feet above sea level, 120 miles n<irth- 

 west of Vancouver. 



This specimen is light in colour, and constitutes a good type of the "yellow" or "flue- 

 grained " variety. The structure is uniform, the section embracing zones 2 and 3. It cuts 

 hard and evenly, but is not particnilarly flintv. A coarse saw, however, throws the summer 

 wood out into (il)\'ions ridges, while a rather fine saw leaves an even and hai'd surface 

 throughout. 



Shakes d\ie to shrinkage are but slightl}' developed and chiefl_y radial, following a course 

 independent of tlie I'ays. Tlie very inconspicuous cup shakes are connected with the star 

 shakes by diagonal fractures. Longitudinal shear is not rejnesented. 



In designating Douglas fir for commercial purposes, the terms "yellow" and "red," 

 "coarse-grained" and "fine-grained," are used to indicate the various qualities. The 

 "yellow" and "fine-grained" varieties are those which possess the highest value for struc- 

 tural purposes, because of their greater freedom from shakes, among other reasons, and 

 these diflerences are shown in the descriptions of 316 and 2. 



