100 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



VI. Thinnings. 1 By M. Broilliard. 



" A thinning consists in lessening the crowded condition of the 

 crowns of the best trees in a canopy, so as to favour their de- 

 velopment." Such was the definition I formulated in 1874, while 

 touring in the high forests of oak in Central France. By great 

 chance I came upon it while looking up a note on the Hardt, 

 and I found it again amongst a few passing remarks noted on 

 the exotics in the Park of Coucheverny, and on the staves and 

 headers of Blois. Have I stated it elsewhere 1 Whether I have or 

 not, this is the general idea that has guided me in the thousands 

 of operations of the kind which I have had to direct since 1854, 

 and to-day it still satisfies my conception, though, like eveiy 

 definition, it remains incomplete, and is even dangerous. Com- 

 paring it with others, starting from the stems to be removed, the 

 idea is seen to be quite different. Let us see the application of it. 



Among our forest trees the oak is the one whose proper bring- 

 ing up is the most difficult, notwithstanding the fact that an oak 

 wood, left entirely to itself, may be sometimes a marvellously fine 

 sight. For an instance one has only to visit the Plantonnee 

 Wood, in the Trongais district, if it still exists ; nevertheless, 

 we cannot look on a lot of oaks two hundred years old, and only 

 19| inches in diameter, while another lot of the same age are 

 twice as thick, without inquiring into the mode of treating the 

 latter. They are not so tall, of course. The former, with boles 

 65 feet long, give about 66 cubic feet of timber each, and are 

 worth £3, 19s. apiece. The latter, with boles only 39 feet 

 long, give 192 cubic feet, and are worth £23, 16s. apiece. The 

 one wood may contain 200 of the smaller trees to every 50 or 60 

 of the larger ones in the other, but, apart from the money gain, 

 the difference in quantity of material on the ground is hot all 

 loss, for many surplus stems will have been taken out in thin- 

 nings. There is no need for speculative argument, however ; the 

 fact is convincing. Slow-grown, soft- wooded oaks of 19 J inches 

 diameter make poor planks, or, may be, a little wood for cooper- 

 age, whereas the trees of greater girth are good for every pur- 

 pose. Let us thin out our crowded oaks; we shall in that way 

 reap other advantages also. 



1 Reprinted, by permission, from the Indian Forester, after conversion of 

 the French into British measures. Cubic contents are expressed in terms of 

 the quarter-girth system of measurement. 



