18 ANNUAL OF SCIENTIFIC DISCOVERY. 



may be summed up as follows : With regard to the forms of rail- 

 way axles, it appeared to him, he said, from the experiments, that the 

 nave of the wheel should not be placed close to, but at some little dis- 

 tance (say three fourths of an inch) from, the neck of the journal ; also, 

 that the shoulder behind the wheel should be entirely done away with ; 

 and, instead of reducing the diameter of the axle in the middle, it 

 would be advisable rather to increase the bulk at that point, like the 

 connecting-rod of an engine. He had never heard of a single case, in 

 which the texture of a fractured parallel axle had been found changed 

 from a fibrous to a granular character, although a certain amount of 

 granulation had been repeatedly observed with axles which had been 

 reduced in the middle, and had then been broken in course of regular 

 working. It appeared in all such cases as if there had been a pro- 

 gressive and alternate action of compression and extension of the outer 

 fibres, from the bending of the axle, whilst it was rotating ; .and that 

 thus the granular fracture had been produced. If a shoulder was left 

 on an axle, it should be curved ; for if it was left square it would in- 

 duce fracture at that part. It would appear that there was a constant 

 progressive tendency to fracture, wherever opportunity was afforded 

 for its commencing. Now a parallel axle did not afford any spot for 

 the commencement of fracture ; on the contrary, the fibres extended 

 unbroken throughout the length of the bar; and, unless, from the undue 

 weakness of the axle, a constantly recurring bending action occurred, 

 by which the whole external fibres were compressed seriatim as the 

 axle rotated, there could be no tendency to break. 



IMPROVED BRAKE. 



MESSRS. KLMBALL & RICE, of Concord, N. H., have patented an 

 improved brake, which has been in use for some months upon several 

 of the cars on the railroad from Concord to Boston, and has given 

 .great satisfaction. The invention consists in placing a tube-coating 

 of India-rubber around a link passing through a box or casing, which 

 is attached to the brake. The rubbe.r is inclosed in the box, to hold 

 it in a permanent position, except so far as its elasticity is affected 

 by the pressure of the link, whenever the brake is used, thereby caus- 

 ing the rubber to act and react within itself without any rubbing or 

 friction of the links in which it is inclosed, thus avoiding the wear 

 and rattling of the machinery, as well as unpleasant shocks Scien- 

 tific American, June 15. 



RAILWAY WHEELS. 



MR. E. CHAMBERS, of Birmingham, has received a patent for some 

 " improvements in the manufacture of wheels." The wheels are each 

 made up first into halves, each half consisting of one half of the ring 

 or felloe, one half of the spokes, and one half of the nave, all of 

 wrought-iron, and the several parts are made as follows : For each 

 half of the nave a block or plate of iron is forged in a cylindrical ex- 

 terior frame, with a flange or projection all round, which flange is to 



