AMERICAN INSTITUTE. 



drew the chain tant and thus applied the braises. In addition to 

 tliis there was a supplementary cliain on the same shaft winding 

 in an ojiposite direction which checked tlie pull at the desired 

 point. The inventor claimed that his device applied the brakes 

 to the last car of tiie train first, to all with exactly uniform pres- 

 sure, and by means of the supplementary chain prevented any 

 possibility of sliding the wheels. The whole affair in order to 

 success must completely ignore the principle of friction in all 

 of the representations as when it was on the public trial a signal 

 failure. The brakes were applied to the first oar with sufficient 

 force to slide every wheel, while at the same time there would 

 be a comparatively sliglit brake on the fourth car. It is not pos- 

 sible so to adjust a compensating chain on the engine as to release 

 the brcikes with certainty at any desired point before sliding the 

 wheels. The variable grades of the road, the different elasticity 

 of the draw heads, the changeable load, &c. &c., make it impos- 

 sible in railroad mechanism so to adjust any device to so nice a 

 point. It is barely possible to obtain such a result with fixed 

 machinery, and I am convinced utterly impossible on railroad 

 cars. It is difiicult to conceive how the inventor could ever 

 imagine that his plan would apply the brake to the last car first, 

 or that he could ever fix a supplementary chain to apply the 

 brakes with full force and not slide the wheels. 



It would seem, Mr. Chairman, that the resources of invention 

 would be nearly exhausted in the production of braking appli- 

 ances for railroad cars, in fact Sir, I think they are. I should 

 consider it a thankless job to undertake the construction of any 

 new car brake. Among all the plans I have seen, and among 

 those I have enumerated, I think Hotchkiss's the best; this ap- 

 plies the friction to the top of the wheel giving it a wider bear- 

 ing. There is only one objection that I can see to it, and perhaps 

 that is of no importance, namely, the narrow space between the 

 top of the wheel and the body of the car. There may be other 

 objections to Collier^s plan in the manner of gearing that will 

 prevent its-coming into use, as I have not examined it closely. I 

 am clearly of opinion, however, that it will bea long time before 

 the present ]ilan of car brakes will be superseded. 



There is one idea about brakes, and by the way, it applies to 

 everything else, it is this, and the great mass of inventors over- 

 look it. It is not enough for a machine to work and accomplish 

 the effect intended; an ingenious mechanic can accomplish almost 

 anything by combiuatious of mechanism. Inventors can so seldom 



