FOREST-CULTURE IN ALPINE RAVINES. 833 



then sowing the seeds of grasses in the intervals. Concurrently with 

 these preliminary operations, the only object of which is to prepare 

 the soil for the reception of the forest-growth to be planted later, 

 the torrent itself is attacked with works intended to impede its course, 

 hold back the drift-matter, and prevent further undermining of the 

 banks. For this purpose wattles and bars are inserted along the 

 stream and its smallest ramifications, beginning generally at the upper 

 j)arts, where the water, not having acquired its full force, can be more 

 easily stopped, and the suspended matter may be more easily retained. 

 Green branches of willow and hazel are woven around stakes in the 

 ravine, take root in the soil, and become a living obstacle which per- 

 petuates itself. If the wattles are close enough together, they will 

 transform the ravine into a kind of staircase, by the agency of which 

 the violence of the water is allayed at each step, its force is lessened so 

 that it does not wear upon the soil, and it is made to run almost clear. 



More energetic measures are required lower down, where the tor- 

 rent exercises a more destructive action. Here dams of masonry are 

 inserted in the banks, provided with an arched channel in the lower 

 part to permit the outflow of water at moderate stages of the stream ; 

 they serve to hold back the stones that are worked out from the moun- 

 tain, to promote the growth of alluvions, to break the fall of the tor- 

 rent and diminish its violence by enlarging its bed. Some of these 

 dams are real works of constructive art, and have cost as much as 

 eight or ten thousand dollars. 



The real replanting of the woods is done after the ground has be- 

 come settled and the torrent has been subdued. Nurseries of young 

 trees suitable for the purpose are previously established near the local- 

 ity of the works, which are drawn upon as the plants are needed. The 

 species vary according to the nature of the situation and the soil. 

 Generally pines and firs of different kinds are best adapted to the 

 higher situations, deciduous trees to the lower ones. Use has also 

 been made of several species of shrubs and bushes, which Avith their 

 branching roots are wonderfully fitted to fix the earth, and by rea- 

 son of their rapid growth quickly furnish a shade to the bare sur- 

 face. The planting is begun at the top of the elevation and is con- 

 ducted downward, in such a manner as to leave no places vacant. The 

 young trees, protected against the sun by the grasses which were 

 previously sown and by the willow-cuttings which have already taken 

 root, soon begin to grow with vigor. An effort was made, in accord- 

 ance with the law of 1864, to substitute regrassing for replanting with 

 wood in the interior of the perimeters ; but it did not answer the pur- 

 pose of consolidating the soil, and was abandoned. Sometimes the 

 communes have shown themselves hostile to the execution of these 

 works on account of the interdiction of pasturage. Such was the 

 case in the communes of Orres and Saint-Sauveur, whose inhabitants 

 drove away the workmen in 1864. The work was resumed three 



TOL. XIX. 53 



