38 STEAM TROLLY. 



call for little further remark. It should be borne in mind that the foot-tons 

 of energy given do not represent the total vis viva oi the train, which must 

 be always a certain amount in excess of the energies tabulated. These 

 amounts — due to the influence of the revolving wheels — are interminable, 

 but must always fall short of the total energies stored up in the wheels, so 

 that they represent at a maximum only a small addition to the total foot- 

 tons. 



"Speaking generally of the experiments, it should be remarked that 

 they were conducted by the gentlemen who had undertaken the work on 

 behalf of Mr. Drummond, with the utmost care, so that perfect reliance 

 ma}^ be placed in the results obtained, excepting so far as certain small ir* 

 regularities were occasionally developed in the diagrams that declare them- 

 selves on inspection of the table, and do not affect the general results. 



"In our article on page 279 of our seventeenth volume, we observed 

 that 'the Westinghouse brake, admirable though its performance was, is 

 -capable of far better things as regards promptness in stopping the train. * 

 * * There can be no doubt that the increased value of the retarding force 

 per second, as compared with the resistance per yard, indicates a want of 

 promptness either in the handling or in the action of the brakes.' These 

 remarks referred to the brake as originally introduced upon English rail- 

 ways b}^ Mr. Westinghouse, and the critcisms we then passed have been 

 found to be fully justified by the great improvement he has since made, and 

 which developed into the Automatic brake, that made its first appearance 

 here at the Newark trials. The work performed by it on the ISIorth British 

 Railway the other day, was generally better than that done on the former 

 occasion, and it would now seem that the sj^stem is susceptible of but little 

 further improvement. The same remark also applies to the Vacuum brake, 

 although, as already stated, the performances on the North British Eailway 

 are not a true indication of its actual capabilities, having been increased by 

 the aid of auxiliary means not used in practice. Still both systems are now 

 before the public in almost their best form ; what they are capable of abso- 

 lutely and relatively doing is now clearly known, and there can no longer 

 be any excuse for hesitation in adopting one or the other of them, oh the 

 alleged want of knowledge as to which is the more efficient of the two. The 

 necessity for some means of controlling trains is proved weekly by acci- 

 dents of more or lees severity upon one or other of our railways, and we 

 fail to see upon what grounds, those with whom the power of adoption rests, 

 fail to make use of means ready to their hands, or why in making a selec- 

 tion they prefer one system that falls 50 per cent, below the degree of ef- 

 ficiency of another." 



STEAM TROLLY. 



Mr. Joseph Green Cooke, the locomotive and car superintendent of the 

 Oude and Kohilkunde Eailway, has constructed a steam troll}'' or carriage, 

 the object of which is to enable resident engineers to inspect their tracks, 

 bridges and works with rapidity without being obliged to travel by train. 

 Its weight being less than 1200 pounds, three men can remove it from the 

 track in fifty seconds, and for that purpose it is constructed in three parts, 

 viz: 1st, its fuel and water boxes; 2d, the boiler, frame, engine and one pair 

 of wheels, and 3d, the front wheels. 



The trolly has one steam cylinder only, this being 3|^ inches in diameter, 

 and 6 inch stroke, and the connecting rod being coupled direct to the one 



