70 ANNUAL OF SCIENTIFIC DISCOVERY. 



gearing 1 ' similar to the above, except that the surfaces are let into each other 

 in grooves. Messrs. Dron and Lawson, of Glasgow, are using this gearing 

 with great success in driving large planers, as it never slips, and is parti- 

 cularly well adapted to easy reversing, &c. 



Leather Bearings for the Axles of Carriages. A recent English patent 

 proposes to use bearings of leather in the place of metallic bearing surfaces ; 

 the object being to render the bearing surfaces of blummer blocks and axle 

 boxes more durable and less costly than heretofore. In carrying out tliis 

 invention, ox or cow hides are preferred, either tanned, tawed, or otherwise 

 prepared ; and for one class of bearing the hides are cut up into pieces of 

 suitable size for lapping half, or nearly half, round the journals to which they 

 are to be applied. These pieces are compressed in half round moulds to bring 

 them severally to shape ; and the required thickness of bearing is obtained by 

 cementing two, three, or more thicknesses of leather together, piling them in 

 layers one above the other, and then submitting the combined thicknesses of 

 leather to pressure in a suitably shaped mould for the purpose of solidifying 

 the same. These bearing surfaces may be backed or cased with metal. 



IMPROVEMENTS IN THE MANUFACTURE OF RAILWAY BARS, 



AXLES, &C. 



Improvements in the Manufacture of Railway Bars. In the process of manu- 

 facturing malleable iron rails as at present practised, the small fragments of 

 puddled iron which are collected together to form a puddle ball are more or 

 less oxidized on then* exterior surfaces, and are otherwise coated or mixed 

 with scoria and other extraneous matters. In the squeezing or rolling pro- 

 cess which follows, a large proportion of these extraneous matters are driven 

 out, but so much of them is often retained as to prevent an equal and perfect 

 union of the surfaces of all the numerous pieces of which the mass of iron is 

 composed. In the operation of rolling, a considerable elongation of the metal 

 takes place, and consequently those parts of the iron which are prevented from 

 uniting by the scoria, oxide, or other matters, are also much elongated, form- 

 ing what are called flaws or sand cracks, and giving a more or less detached 

 or feebly coherent lamellar texture to those parts of the iron. The rolling of 

 heavy wheels over such a material, tends to elongate the upper stratum, 

 which ultimately becomes loosened and detached from the general body of the 

 rail, and which defect is augmented by the soft and malleable condition com- 

 mon to iron that is entirely deprived of its carbon. Mr. H. Bessemer, of Lon- 

 don, proposes to lessen or remove these defects, and produce, as nearly as may 

 be, a homogeneous mass of metal, free from the admixture of oxide, scoria, 

 &c., and at the same time combined with as much carbon as will give it 

 greater hardness and power to resist the laminating action of the wheels which 

 pass over it. In practice, refined iron is put into the ordinary puddling fur- 

 nace, where it is at first treated in the usual way, being raked about until it 

 has thrown off the greater part of its carbon; but care should be taken not to_ 

 carry this process of decarbonization too far ; about 1 per cent, of carbon should 

 be retained. A knowledge of the most advantageous point to leave oft* the 

 puddling operation will be readily acquired in practice, a good test to the work- 



