170 History of Mechanical Inventions, Src. 



4. Description of new Axle-Trees for remedying the extra friction on Curves 

 for Waggons, Carts, Cars, and Carriages, and on Rail-roads, Tram- 

 ways, and other Public Roads. By Mr Robeet Stephenson. 



It has been long felt as a serious inconvenience and loss, that the curved 

 parts of rail-roads are speedily worn down by the enormous friction of 

 waggon wheels of the common form) and require to be replaced long before 

 the straight portions aie injured. 



The object of Mr Stephenson's invention (which is secured by patent) 

 is to remedy this evil ; and he has succeeded so completely, that his wheels 

 will roll round the sharpest curve without any additional friction from the 

 sliding of the wheels. These wheels, each of which revolves upon an axle 

 of its own, are shown in Fig. 5, Plate I. which is a horizontal view of 

 the carriage of a railway waggon, where b, h, &c. are the wheels, and 

 a, a, a, a, their axles. The end of the axle which is nearest the wheel 

 turns in a long slot or recess seen below d in Fig. 6, while the other end 

 c of the axle has affixed to it a ball or spherical knob, which turns in a 

 socket in the opposite bearing. By this construction the wheels revolve 

 independently of one another, and a difference in the paths which their 

 rims describe will not cause them to rub or slide upon the rail. As rail- 

 roads are never perfectly level, the long slot allows the axle and its wheel 

 to fall, as at A, Fig. 6, the ball and socket joint at the reverse end giv- 

 ing it play. Mr Stephenson does not mean to confine himself to the ball 

 and socket strictly, as several other modes of constructing a loose joint may 

 answer the purpose ; but he claims as his invention " the double axles, 

 and the mode of giving them play, by the loose joint at one end of its bear- 

 ing, and the slot at the other." — See Newton's Journal of the A?is, vol. xi. 

 p. 169 and p. 200. 



5. Description of Union or Compound Rods in which Wood and Metal arc 

 combined so as to form Rails or Rods for Bedsteads, Cornices, S$c. By 

 Mr Samuel Pratt, New Bond Street. 



This invention promises to be of very great utility for producing strong 

 but light rods for the slender parts of furniture. The rods, &c. are first to 

 be made of wood to the desired shape, and the wood is then split or sepa- 

 rated lengthwise into three pieces, and after some parts of the interior of 

 the wood are removed, a bar of iron with three leaves is introduced, and 

 the three pieces of wood united again by glue or otherwise, with the three- 

 leaved bar inclosed. A section of these bars is shown at A, B, C, Plate I. 

 Fig. 7, where A is a section of a rod ready to be operated upon. It is then 

 divided and finished as at B, the iron rod having the form shown at C 

 The patentee proposes to coat the iron rods without wood, with cylinders 

 of thin brass drawn over the outside of the rod, so as to give them the ap- 

 pearance of solid rods of metal, as shown at D. — See Newton's Journal of 

 the Arts, vol. xi. p. 183. 



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