14 



TRANSACTIONS OF THE 



[NOV. 3. 



that the rails assumed delinite forms in tlie track due to their 

 permanent set. The extent of the permanent set in the rails, or 

 the rapidity of its taking place, has quite delinite relations to 

 the section of the rail, weight per yard, Itallast, system of laying 

 the joints, traffic and care the rails receive in the track. 



The care and finish of rails in manufacture is also an impor- 

 tant element, increasing in its noticeable eifects as the stan- 

 dard of track rises. The smoothness of the surface of rails 

 determines to a great extent the degree of perfection the track- 

 men can sm-face the rails ; they can remove long bends, but not 

 the short ones in the rails. I have classified to date the perma- 

 nent set found in rails under three principal Pi'imary Forms, 

 represented by cuts numljers 6, 7 and 3 ; there are often com- 

 binations of the 1st and 3d, and the 2d and 3d. 



Forms of wear are quite distinct from these, though, when 

 the steel is not homogeneous, one form appears on the surface 

 somewhat like cut No. 3. 



lor. ftr !. 9 rT.po!n wsv * r IfnJ* 





Cut No. 4 shows, to some extent, the characteristic deflections 

 or undulations which even the smootliest rails assume under 

 heavy cars, due to looseness and unequal tamping of the ties ; 

 with double-angle plates in good condition, the wave of one rail 

 is carried to the succeeding one, practically making a continu- 

 ous RAIL. 



Rails like No. 4 appear in good surface when not under 

 trains, and are really wliat sliould be called the Third Form. 



