DEMAND FOK WOOD. 
293 
and, finally, furnish an inexhaustible and self-renewing supply 
of a material indispensable to so many purposes of domestic 
comfort, to the successful exercise of every art of peace, every 
destructive energy of war.* 
But our enumeration of the uses of trees is not yet com¬ 
plete. Besides the influence of the forest, in mountain ranges, 
as a means of preventing the scooping out of ravines and the 
accumulations of water which fill them, trees subserve a valu¬ 
able purpose, in lower positions, as barriers against the spread 
of floods and of the material they transport with them; but 
this will be more appropriately considered in the chapter on 
the waters; and another very important use of trees, that of 
fixing movable sand-dunes, and reclaiming them to profitable 
cultivation, will be pointed out in the chapter on the sands. 
The vast extension of railroads, of manufactures, and the 
mechanical arts, of military armaments, and especially of the 
commercial fleets and navies of Christendom within the pres¬ 
ent century, has greatly augmented the demand for wood,f 
* The preservation of the woods on the eastern frontier of France, as 
a kind of natural abattis, is also recognized by the Government of that 
country as an important measure of military defence, though there have 
been conflicting opinions on the subject. 
f Let us take the supply of timber for railroad ties. According to 
Clave (p. 248), France has 9,000 kilometres of railway in operation, 7,000 
in construction, half of which is built with a double track. Adding turn¬ 
outs and extra tracks at stations, the number of ties required for a single 
track is stated at 1,200 to the kilometre, or, as Clavd computes, for the 
entire network of France, 58,000,000. As the schoolboys say, “ this sum 
does not prove; ” for 16,000 4- 8,000 for the double track halfway = 
24,000, and 24,000 X 1,200 = 28,800,000. According to Bigelow (Les Etats 
Unis en 1863, p. 439), the United States had in operation or construction 
on the first of January, 1862, 51,000 miles, or about 81,000 kilometres of 
railroad, and the military operations of the present civil war are rapidly 
extending the system. Allowing the same proportion as in France, the 
American railroads required 97,200,000 ties in 1862. The consumption of 
timber in Europe and America during the present generation, occasioned 
by this demand, has required the sacrifice of many hundred thousand acres 
of forest, and if we add the quantity employed for telegraph posts, we have 
an amount of destruction, for entirely new purposes, which is really appalling. 
The consumption of wood lor luciler matches is enormous, and I have 
