104 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



increment, it induces the sustained development of magnificent 

 trees. The silver fir, though resisting indefinitely the pressure of 

 its neighbours, often finds itself too crowded as it advances in 

 age, and it is a good deal better off for a little thinning out of 

 trees of the same height; but the work must be gradual, for 

 sudden changes of condition are dangerous. This species loves 

 tranquility; it amplifies its foliage but slowly, and never much; 

 it likes coolness and freshness, and suffers from the introduction 

 of sun and wind. Thus, if isolated after being brought up in a 

 canopy, it dies. We cannot alter nature. The silver fir loves a 

 close canopy; let us take good care never to open it out. I, 

 myself, coming from woods of pine and larch, was at first too 

 bold among the silver firs, too much inclined to give them an 

 excess of air, as is commonly and wrongly said, instead of light 

 and space. There was a compartment " M " of the forest of 

 Grand' Cote, on a poorish soil with scattered boulders. Here I 

 made a rather severe thinning. The felled stems fetched one 

 penny each. Fortunately the poles were quite young, and we 

 preserved the underwood. Feeble benefit on all sides, and a 

 dangerously excessive thinning ! After this experience I became 

 more cautious in dealing with silver firs. 



Among the spruces it is again different. This species is some- 

 what cosmopolitan; it can flourish equally well as an isolated 

 tree on a pasture, or in close canopy. Yes, provided it has 

 been brought up to it. In close canopy its roots are as scanty 

 as its wig ; if it is isolated late in life, the roots are wrenched 

 about and the tree dries up. Our friends, the Swiss foresters, 

 led on by enthusiasm, are perhaps trying how far they can go. 

 The idea of thinning, par le haut, could not originate in spruce 

 forests, and if I have contributed towards spreading it so far, I 

 should, nevertheless, be sorry to see it carried to extremes. The 

 thinning among the tops is indeed useful to spruce, but this 

 species is certainly the one that has least need of it, and can do 

 very well without it. For instance, see the splendid forests of 

 the Ebenwald (Revue of 15th August 1898, p. 520), 320 to 360 

 stems to the acre at 130 years eld. There are also instances in 

 France of forests that have never known a thinning. The rate 

 of vegetation per tree is exceedingly slow, but what splendid 

 sawyer's wood ! And what a growing stock peacefully slumbering 

 on foot ! up to as much as 12,900 cubic feet per acre at 120 years 

 old. At 7^d. the cubic foot the stock is worth £390 per aci'e, 



