ON AMERICAN PERMANENT WAY. 601 



from three to five years, and cedar eight to ten years, hnt the latter being 

 so soft a wood will only stand light service on easy grades. Timber will 

 last mnch longer in a severe climate where it is frozen up uniformly for 

 many months in the year, than it will in a temperate climate, exposed to 

 alternate freezing aud thawing. 



The following is the standard specification of the Pennsylvania Kail- 

 road for cross-ties as adopted January 1, 1879 : — 



' 1. All ties must be made of green or living timber, of good quality, 

 and free from decayed knots or other unsound parts. White oak and 

 rock oak will be the only kinds of timber admitted. 



'2. Ties must be eight and a half feet long, seven inches thick, and 

 not less than seven inches wide ; to be hewn on two sides with straight 

 faces, of an even thickness, sawed off square at each end, and stripped of 

 the bark. 



' 3. No variation will be allowed in the length and thickness given 



above. 



' 4. No sawed or split ties will be received. 



' 5. They must be delivered on the line of the railroad, stacked up in 

 neat sqnare stacks of fifty each, with alternate layers crossing each other, 

 on around which is as high or higher than the grade of the road, and in 

 such position as to admit of being counted and inspected. 



' 6. Ties delivered at suitable and convenient places, will be inspected, 

 and bills made for all received and accepted to the fifteenth of each 

 month. The payments will be made on or about the fifteenth of suc- 

 ceeding month.' 



The number of ties used for each 30-feet rail are— for main running 

 tracks, sixteen ties ; for branch roads and third tracks on main lines used 

 exclusively for freight trains, fourteen ties ; and for sidings and tracks 

 used for standing cars only, not exceeding twelve ties. 



The Grand Trunk Railway of Canada uses ties 8 inches flatted face, 

 by 6 inches thick and 8 feet long, 2,610 to the mile. The material 

 is white oak, hemlock, or tamarac, the former now becoming very 

 scarce. White oak lasts ten to twelve years, and the other woods about 

 six years. 



The Atlantic and Pacific Railroad ("western division) uses ties 

 8 inches by 6 inches by 8 feet long, mostly native pine, but on heavy 

 grades and curves oak ties are used ; number to the mile, 2,81<>. 



The Cincinnati Southern Railway specifies tie's ' of either white, post, 

 burr, or chestnut oak, or other timber approved by the engineer, cut from 

 sound live timber, free from rotten or loose knots, worm-holes, dry rot, 

 wind-shakes, or other imperfections affecting the strength and durability 

 of the wood. All bark must be removed. They must be 8 feet in length, 

 not less than 6 or more than 6h inches in thickness ; one-fourth the num- 

 ber must measure not less than ten inches face for the entire length of 

 the tie, and the remainder not less than 8 inches ; the faces must be 

 parallel, not winding, smooth, free from deep score-marks and splinters. 

 Ties must be cut squai-e at the ends, and be straight in all directions. 

 Not more than one inch of sap will be allowed on the face of sawed ties. 

 2,640 ties are used to the mile of single track.' 



The standard hard-wood ties of the Chicago and North-Western 

 Railway have the following order of value : white oak, burr oak, red elm, 

 cherry, black ash, and butternut. They are 8 feet in length, and 6 by 8 

 inches section if sawed, or 6 inches thick with 6 inches face if hewn. 



