MECHANICS AND USEFUL ARTS. 41 



that when the switch is set wrong, the cars cannot run off the track." 

 The safety-switch has been introduced upon the Hartford, New Ha- 

 ven and Springfield, the Boston and Providence, the Boston and Low- 

 ell, and other railroads. Editors. 



IMPROVED RAILWAY CHAIRS AND SWITCHES. 



BOTH of these improvements are the invention of Mr. Baines, who 

 described them before the Royal Society, where they excited conside- 

 rable interest. The peculiarity of the chairs consists in an arrange- 

 ment whereby the joints are prevented from rising or getting out of 

 the line, and the rails from driving forward. To effect these objects, 

 the outer jaw of the chair is made to fit close up to the under side of 

 the head of the rails, but the inner jaw is only of sufficient height to 

 clip the bottom flanch, and the rail is not fixed by a key, but by a square 

 wrought-iron dowel-pin, which passes through a hole in the outer jaw 

 of the chair and a corresponding notch in the end of each rail. This 

 pin has a large flat head, and under the head is placed a wrought-iron 

 plate, 9 inches long, which fits close up to the head of the rail on the 

 inner side, and rests on the chair. A square cotter or wedge is then 

 driven vertically through the outer end of the dowel-pin, which draws 

 the whole firmly up to the outer jaw of the chair. The wrought-iron 

 plate is three quarters of an inch thick in the middle, tapered to the 

 ends, and slightly cambered or arched, and is sprung flat by driving 

 the cotter, which is made long enough to drive through the bottom of 

 the chair into the sleeper, and serve as the spike on the outer side of 

 the chair. A slot is made in the upper part of the cotter, to allow it 

 to be drawn out when required. The pressure of the wheels has no 

 tendency to loosen the fixing of the rails in the chair, as the outer jaw 

 fits close to the head of the rails, while the bottom flanch is firm- 

 ly clipped by the inner jaw, as we have before mentioned. The 

 dowel-pin does not receive any of the pressure of the wheels, but 

 holds the rails against the outer jaw, and also prevents them from ris- 

 ing at the point and from driving forwards. The effect of the long 

 plate under the head of the dowel-pin is to connect the two rails stiff- 

 ly together, so as to prevent the working of the joint. Another part 

 of the invention is an intermediate chair, whose jaws are alike, but set 

 obliquely, instead of opposite each other. It is slipped endways on the 

 rail, and then twisted at right angles to it, which causes it to grip it 

 firmly between the jaws. It is held by means of spikes. 



The improvement in switches consists principally in making the 

 tongue about half an inch deeper than the rail, so that it may work 

 under it, by which means steadiness is secured. During the discus- 

 sion which took place, it was stated that an experiment had been tried 

 with the chairs for nearly a year on the Norfolk line, where the whole 

 of the ballast was taken away from the joint-sleeper, and there was 

 then only a slight deflection, so that the trial was entirely satisfactory. 

 London Mining Journal. 



4* 



