PROTECTION AGAINST DRIFTING SNOWS. 283 



cause the snow, driven by the wind, in eddies more or less thick, tends to fall where 

 tue disturbance of the air is less felt, that is, in trenches and on the slopes of hill(>, 

 where it rapidly piles up to the level of the country adjacent, and renders expensive 

 labors necessary to open the way, so as to make it passable for teams. But the way 

 is scarcely opened before it disappears again, as soon as the wind begins to blow, so 

 as to carry the snows before it. 



This eftect was seen with remarkable intensity before 1849 iipon the imperial road 

 No. 82, of Roanue-on-the-Rhone, between Saint-Etienne and Bourg-Argental, upon 

 the plateau called De la R6publique, at the great turn near the village of Ruthiange. 

 At this part of the route the road rises from a point 537 meters (1,77'2 feet) to an ele- 

 vation of 1,140 meters (3,740 feet) above sea-level, to clear the Pila Range at the ridge 

 ot Grand-Bois, from which it descends toward Bourg-Argeutal by following the left 

 bank of the Argental Brook, in the course of which it crosses several secondary ravines 

 which join this stream. The storms reign in these elevated regions with a violence 

 elsewhere unknown, and the snows, borne by the winds, are rapidly carried great dis- 

 tances and dropped into the ravines to the depth of many hieters. The road then 

 wholly disappears under tho banks of snow, and the traveler has nothing to guide his 

 way but the pyramids of stone built at certain distances apart along the way, and 

 the interruption of travel has been so grave an inconvenience, that the mail post from 

 Paris to Marseilles has been obliged sometimes to wait at Saint-Etienne for the road 

 over the Pila to be cleared, before pursuing its course to Roanne-on-the-Rhone, at a 

 cost sometimes of 5,000 francs, to say nothing of losses to private credit and business 

 intrusted to the postal service. 



The road was more particularly intercepted upon the naked plateaux, or upon the 

 more steeply inclined slopes, where there was no shelter from the north winds, but 

 throngh the woods the travel was never interrupted, however severe the storm, and 

 the track when once broken through remained open all winter. But in the exposed 

 parts of the road the trenches were hlled up as soon as they were made, and it became 

 necessary to work day and night to keep the road open for travel. The mail post 

 could only be got over with incredible efforts, drawn by 10 yoke of oxen, or from 10 

 to 15 horses, and requisitions were often made upon thp inhabitants of the vicinity 

 and their teams, yet without advantage. 



The idea of sheltering the road by planting trees very naturally presented itself. 

 The project was studied to this end in 1847, and put in execution 'some years later. 

 Those parts of the road where the circulation was always interrupted during the 

 stormy season have been sheltered by four massive plantings of evergreen trees, which 

 are more closely set in the steeper plopes. Their breadth varies from 27 to 83 yards. 

 Two of these screens have been planted on the plateau De la R^publiqne ; the first 311 

 yards long and 37 to 76 yards wide, and the other 1,217 yards long by 36 yards wide. 

 The two other screens are along the Grand Tournant, on a very steeply inclined sur- 

 face, and are 360 and 235 yards long, and 4S to 50 yards wide. 



These plantations were begun in March, 1849, and were continupd to the end of 

 April, 1851. The trees selected were evergreens of various kinds, such as spruces, 

 European and American silver fir, larico pine, &c., and the larch, set about a yard 

 apart. When planted, they were from 20 inches to 4 feet in height ; the smaller ones 

 forming the first row along the roadside and the larger being placed a little farther 

 back. They were all planted with the ball of earth adhering to their roots, and were 

 delivered the next day after they were taken from the nurseries, being supplied by M. 

 S6n6clauze, nurseryman at Bourg-Argental, who undertook the contract for planting. 

 The area planted was a little less than 15 acres, and the cost amounted to 37,174^ 

 , francs, or about 2,478 francs per acre, divided as follows : 



Franca. 



Purchase of land 14,381 83 



1.171^ meters of excavation for planting, at 1.144 franc 1,239 42 



42 380 trees, at 0.455 franc 19,282 90 



1,767 trees broken by the snow, at 0.455 franc 803 98 



32,227 guardian trees (tuieurs), at 0.455 franc 1,466 32 



22, 792 63 



Total 37.174 45 



These plantations were scarcely finished when the result surpassed the hopes that 

 had been formed, and the very firet year the snow was retained by the young fir trees 

 so that it did not drift the road that was to be protected. Since then, the movement 

 of the winds has been more and more interrupted, and in proportional degree the ex- 

 pense of opening the road has been leduced, so that it is now quite easy to keep it 

 open for travel through the worst seasons. The trees are now growing very vigor- 

 ously, and some had increased more than a. yard in height in 1858, completely assuring a 

 dense massive growth in the future. Each of the tracts planted is surrounded by a 

 deep ditch, the soil from which >vas thrown inward toward the trees, to prevent cattle 

 fToai reaching them. 



