30 ANNUAL OF SCIENTIFIC DISCOVERT. 



THE CONTINUOUS RAIL. 



Our readers are aware that a continuous or compound rail has been for 

 some years employed on various railways; that it has made an obviously 

 improved, smooth, and easy-riding track, when new, at least, and that it is 

 still largely used on the New York Central and other lines. But the general 

 impression is, that it has not proved remarkably successful, if, indeed, it has 

 not decidedly failed. A very brief review of the history of continuous rails, 

 however, and of the circumstances of American roads, will show that the 

 plan is a decided improvement in every particular; that its first cost, and 

 renewals, and the repairs of the rolling stock carried by it, are much less 

 than in the case of the common rail. 



The first continuous rail was the common rail split vertically from top to 

 bottom the two nearly equal parts breaking joints with each other, and 

 fastened together with rivets. In case of wheels worn on other and differ- 

 ent sized rails, the whole bearing might come on one of these parts, rapidly 

 crushing it, and prying the two apart. The lamination of the inside edges 

 still further sundered the two bars, and the frost rapidly split them apart, 

 breaking the rivets. This rail was impracticable, although for a few months 

 it made, the best road ever laid. "While it was good, and before it had seri- 

 ously deteriorated, it was believed to have saved enough repair expenses of 

 way and machinery to have nearly paid for its extra cost. The next plan of 

 continuous rail had a split head and a solid foot, half the section of the 

 head resting on the foot of the other half. The abrasion of the iron upon 

 iron, in the absence of rigid connection between them, soon destroyed this 

 rail, but it manifestly decreased the repair expenses of machinery. A suc- 

 cessful continuous rail was then brought out, which had a split foot and a 

 solid head, the small section of the foot forming a sort of continuous splice, 

 or bracket-joint. This has been in service for above six years on the New 

 York Central. It is to be regretted that that company has not kept a more 

 definite record of the influence of the continuous rail on the repair expenses. 

 The obvious results of long practice, however, are such that it is still largely 

 used, and that the manner in which it eases the shocks usual at the joints 

 of common rails, and its uniform elasticity, have made it a decidedly paying 

 investment. But the philosophy of permanent way, as deduced from the 

 general experience, is more conclusive. No one will dispute the fact that 

 the thorough ballasting and drainage of the road-bed will allow the use of 

 such a high rail as can alone be thoroughly spliced at the joints. But this 

 high rail is necessarily rigid, and if not supported by an even bed of ballast 

 and sleepers, will bring its bearing on widely distant parts of the road-bed, 

 since it cannot yield so as to bear on all parts; hence the rail will perma- 

 nently bend and rapidly deteriorate, and, when both rigid and rough, will 

 form the worst imaginable track. The experience with the seven-inch rails 

 on the body-ballasted part of the Camden and Amboy line proves this, while 

 much heavier rails on the English well-ballasted lines outlast light rails on 

 the same road-bed. A light, yielding rail, however, on a mud road-bed, will 

 adapt itself to the churning of the sleepers, and take a bearing on the whole 

 of the bed. It will not permanently set when sprung and twisted, and if it 

 becomes bent on a very bad line, it will not be both rigid and rough, but 

 will be somewhat elastic under the wheels. It appears, then, that we must 

 have either tolerable ballasting and drainage, a good road-bed, or else a 

 shallow and yielding rail. Since our managers are either too limited as to 



