54G JOURNAL OF FORESTRY 



various annual expenses — taxes, protection, cost of administration, 

 road maintenance, reforestation, etc. This amounts on an average to 

 15 francs. It is, besides, advisable to allow for accidents which may 

 happen to the trees and which diminish their value, such as windfall, 

 snow breakage, fungus, etc. Placing this loss at 10 per cent (of the 

 annual increase), it will be 14 francs; this leaves a final net revenue of 

 140 — (15 + 14) = 111 francs. 



On the other hand, to the value of the material of 20 cm. and over 

 (3,038 francs), it is necessary to add the soil value and that of the 

 young growth under 20 cm. ; this value can be estimated at 600 francs. 

 The total initial capital then becomes 3038 -|- 600 = 3.638, and the net 



rate of interest yielded . ^ X 100 = 3.05 per cent. 



The yield in number of trees given in Table 3 is, in round figures, 16 

 trees, of which 8 have the siz.e (I) 20 cm.. 5 the size (II) 25 to 30, and 

 3 saw timber (III), 33 cm. and over. If it is considered that the size 

 of the II class is not fixed, and that then saw timber (III) contained 

 some wood of 30 cm., it is certain that this proportion (i. c, 8:5:3) 

 is quite similar to certain eighteenth century working plans, as, for 

 example, in the plan of January 31. 1750. for Rambervillers. where it 

 is said: . . . "Permit to cut 6.000 fir trees, of which one-half are 

 Class I. one-quarter Class II. and one-quarter Class III." 



4. Rccruitiiif/ the Yield 



The normal type of stand is established and the yield fixed; it now 

 remains to recruit this yield among all the diameter classes, propor- 

 tionally to the figures in columns 6 or 7 of the preceding table, accord- 

 ing to whether the yield is by trees or by value. 



This kind of recruitment is assuredly quite delicate ; many foresters 

 consider it even impossible. We feel, on our part, that one can in the 

 marking come near this aim. with a sufficient approximation . . . 

 very generally, when the tabulation of trees marked is compared with 

 the stock-taking before the cutting, one finds that trees of all classes 

 have been marked in the proportion found in the stand. Then, if the 

 stand is "normal" and if' one cares to see to the proper spacing of the 

 trees — that is to say. to have them spaced approximately 15 times their 

 diameter (d. b. h.) — one is greatly surprised at having recniited his 

 vield about in the proportion desired. 



During the marking one can. on the other hand, rapidly keep count, 

 if the three classes of trees (marked) are in the proportion 8:5:3. 



