Page:Popular Science Monthly Volume 29.djvu/633

Rh railway-ties in the road-bed are of necessity in about as favorable conditions for the growth of the fungi as could be selected, and consequent decay is not only probable but certain and rapid. Ties of the most durable woods, as a rule, only resist decay for from eight to ten years, while inferior qualities only last from four to seven years.

The consumption of ties by our railway system will closely approximate eighty million the present year for repairs, and, as these require to be cut from special trees from thirty to sixty years old, ten to sixteen inches in diameter, will take many trees which, in as many more years, would yield from six to eight times as much timber. This rapid reduction of the prospective timber-supply is one of the serious phases of the question, and is causing grave apprehension as to the future sources of ties, not only to the railway officials, but to all persons who look to the general welfare of the country. Transportation now is so intimately connected with every business, and its cost so much a part of the price of nearly all articles, and especially of food-supplies, that the increasing cost of ties becomes a subject of national importance. The American Forestry Congress is urging the planting of trees and the better care of existing forests. While the measures it urges may help the supply of timber twenty-five or thirty years hence, they can not meet the exigencies of the case in the mean time. Railway-ties only last from one fourth to one tenth of the time required to grow them, and the forests are now being rapidly cut to furnish the supply. Very few of the railway companies are in a position to grow their ties; but, as consumers of such vast quantities of timber annually, they can take more effective measures to stop the growth of the fungi and check the enormous wastes of timber now taking place.

One important step, when storing ties and timber before using, would be to put down blocks or timbers for each end of the piles to rest upon, leaving an air-space underneath, and pile the ties an inch apart. This would permit a circulation of air and prevent the growth of mycelia, which is so frequent on the first, second, and third layers, when placed directly upon the ground. When this is not done, the fungi grow as much in the ties, in two or three months in the summer, as they would in one or two years in the road-bed.

There is one phase of decay in ties which has been generally overlooked; in fact, it would not be noticed except by making special examinations. A slight fermentation, which would only soften or make the fiber brittle under a rail or around a spike, becomes of greater importance in ties than in beams which have a large factor of safety. Ties of many species of wood, when sound, will cut under the rails to some extent, and the rate will be much increased, in case the fibers are softened or weakened by fermentations; this I found to be the fact in several hundred chestnut, oak, and yellow-pine ties which had been removed from the track, on account of abrasion under the rails, and of mechanical injury by repeated spiking. Either side of the rails