OF RAIL-ROADS.

55

in contact, or with which it is joined. Thirdly, to form thejoinings of the rail with the pedestals or props which sup-port them, in such a manner, that if these props should varyfrom their perpendicular position in the line of the way,(which in other Rail-ways is often the case) the joinings ofthe rail with each other would remain as before such varia-tion, and so that the rails should bear upon the props asfirmly as before. And the rails being applied to eachother by what is called a half-lap, and the pin or bolt ofwhich fixes them to each other, and to the chair in whichthey are inserted, is made to fit exactly a hole which isdrilled through the chair, and both ends of the rails, at sucha height as to allow both ends of the rail to bear on thechair; and the bearance being the apex of a curve, theybear at the same point. Thus the end of one rail cannorise above that of the adjoining one; for, although the chairmay move on the pin in the direction of the line of the road,yet the rails will still rest upon the curved surface of thebearing without moving.”

This plan of joining the rails is evidently agreat improvement over the common modeand has been almost universally adopted on allnew lines of road; the blows and shocks to whichthe carriage-wheels were exposed in the other,has been almost entirely exterminated in thisplan; and the benefit is not confined to thecarriages alone, for the reaction of those shockswere often liable to break the rails in return.The difference is very sensible in passing alongthe two kinds of rails in carriages; on the oneyou travel smoothly along, with scarcely the