CONTINENTAL NOTES — FRANCE. 43 



mixed with spruce for this reason. The spruce is authoritatively 

 stated to be a good tree to mix with many species, but except 

 in more than ordinarily wet places (where it may be directly 

 useful by removing the excess moisture) one would think that 

 the statement must require some qualification, and that a further 

 attentive study of the effect of spruce upon its neighbours would 

 be worth while. 



III. M. Huffel, the Nancy professor, quotes the results of a 

 very interesting experiment in thinning spruce, made by Herr 

 Schiffel in Austria. Four experimental areas, of nearly 200 

 acres each, were established for purposes of comparison in 1892. 

 The altitude was something over 1800 feet; the ground level ; 

 the soil good and deep, over gneiss ; the age about 80 years. 

 Hitherto these areas had been moderately thinned, and Plot I 

 was continued on the same lines. In 1893 Plots II, III and IV 

 were thinned so as to reduce the basal area of the trees to 

 80 % of that of Plot I. In 1898 Plots II, III and IV were 

 thinned so as to have basal areas of, respectively, 80 %, 65 % and 

 50 % of that of Plot I. Two years later Plot IV was so much 

 damaged by the wind as to throw it out of the experiment. 

 In 1903 a similar thinning was made in the other plots; and 

 again in 1908. Then the data acquired were tabulated and 

 considered, with the following results : — 



1. One can, in a forest of the kind mentioned, reduce the 

 volume of the standing timber by about a third by very heavy 

 thinning without diminishing the production in volume. 



2. These very heavy thinnings, far from spoiling the develop- 

 ment in height, are, on the contrary, favourable to it. 



3. These thinnings considerably augment the growth and the 

 rate of increase in diameter and volume, so that by thinning 

 heavily we obtain a return in material equal, or even superior, 

 with a smaller uncut capital. 



4. The thinning favours the growth of the medium stems. 



M. Huffel says that had Herr Schiffel extended his calculations 

 to the value of the production he would have seen that the 

 influence of the thinning on the financial return is even greater 

 than on the return in material. These results completely bear 

 out those of a similar experiment made by M. Huffel himself in 

 the Vosges. But M. Huffel adds a word of warning — we must 

 be careful not to generalise too fast from experiments made in 

 specially chosen spots ; heavy thinnings, he says, are not possible 



