. > / o 



ARBORICULTURE 



The driving of a railway spike into a 

 wooden tie pushes aside the fibers of the 

 wood and forms an elastic cushion for 

 each spike, while the wood itself forms an 

 elastic foundation over which the traffic is 

 borne in safety. 



Hard woods, as in some of the tropic 

 growths where ties must be bored before 

 spikes may be driven, are ver}'- much less 

 flexible and are inelastic for want of this 

 cushion. 



The slow process of removing bolts and 

 replacing them, in case of accident or in 

 change of track which may become neces- 

 sary, is a serious objection to the use of 

 bolts as fastenings for cross ties. 



Iron and steel are rapidly corroded by 

 oxydation when in the presence of moist 

 earth, and while paint or an asphaltum 

 coating may protect for a while, yet these 

 substances are destroyed by moisture and 

 the acids ever present in soils, leaving the 

 metal unprotected. The increasing use of 

 electricity on railways, even the quantity 

 generated by engines for lighting, hastens 

 this process of corrosion since there is a 

 direct current between the trains and 

 earth through rails and ties. If the latter 

 be of metal, both bolts and metal ties 

 must be rapidly weakened by this rusting 

 ing process, yet hidden from view it may 

 be after some serious accident that the 

 discovery is made. 



On some European railways steel ties 

 are in use, but conditions in Europe and 

 America are very different. Scarcity of 

 wood and high price of ties on account of 

 transportation for great distances make it 

 specially desirable that some substitute be 

 adopted. Lower wages for labor encour- 

 age a greater use of metal. Straight 

 tracks within minimum grade, more sub- 

 stantially constructed roadbeds, shorter 

 lines of roadway, dense population and 

 lighter traffijc, with greater care in all 

 operating departments, combine to dis- 

 courage the use of wooden ties which 

 must largely be brought from America, 

 where the demand is already greater than 

 the supply, and 'make possible in Europe 

 the use of metals which on American lines 

 will long remain impracticable. Dense pop- 

 ulation, greater support per mile of roads 

 operated, low rates of interest, and finan- 

 ciers who are satisfied with smaller divi- 

 dends, place European roads on a differ- 

 ent footing from those of the United 

 States. Yet it has not been decided in 

 Europe that metal ties are profitable, nor 

 how durable and economical they may be 

 as compared with ties of suitable wood. 



One railway in Mexico has part of its 

 track tied with steel. Many of these ties 

 are cracking, while the fastenings are 

 easily disarranged, being secured with 

 keys driven into raised projections which 

 are punched through the sheet of steel 

 and bent upward to receive the rail 

 flanges. 



The trains have a rigid motion, less 

 pleasant to the traveler than those of 

 other roads which have elastic wooden 

 ties. 



The life of wooden ties has been grad- 

 ually shortened in the past two decades 

 because of the inferior wood used in their 

 construction. 



Formerly none but the best heartwood 

 of the trunks of large white oak trees 

 would be accepted. As timber became 

 more valuable for lumbering, the tops, 

 small immature trees, and knotty por- 

 tions were accepted by the inspectors while 

 competition became great among purchas- 

 ers for various railways. 



Rock Oak and various forms of the Red 

 and Black Oak families under sundry 

 names, were received in certain propor- 

 tions, and many roads were glad to secure 

 chestnut, pine, redwood and many other 



