46 ANNUAL OF SCIENTIFIC DISCOVERY. 



and take off the superfluous metal with a slotting or planing machine, 

 than to allow a smith to spend his time in attempting to work exactly 

 to drawing. In textile machinery, however, there is an immense 

 quantity of work to be done, of a slight character and uniform dimen- 

 sions. To suit this kind of work, a forging machine has been invented by 

 Mr. W. Ryder, of Boltou. Eng., and was exhibited at the Great London 

 Exhibition. The machine consists of a strong cast-iron frame, carrying 

 a driving shaft. On this shaft are forged eccentrics, which give motion 

 to swage-holders situated above it. These swage-holders are guided 

 vertically by the frame, while the motion required by the eccentric is 

 allowed for by pieces, the toes of which work in the hollow on the top 

 of the swage-holder. Each swage-holder is provided with a spiral 

 spring, which bears on a key fixed in the frame, and raises the swage 

 after the eccentric has depressed it. A slot is cut in the swage-holder 

 to allow it to slide on the key. Machines of this class are always 

 liable to breakage from a bar of too large a size being put between the 

 swages. This can only be remedied by allowing some elasticity, which 

 in this case is ingeniously effected by inserting a piece of cork in the 

 lower swage-holder, which can be compressed by a screw to any degree 

 of hardness. By another screw, also, the lower swage can be lowered 

 bodily, whenever it is required to vary the size of work to be executed. 

 One of the tools forms a pair of shears to finish the work to a proper 

 length, and by moving a handle which acts upon an eccentric, the 

 lower tool can be raised to meet the upper one. This arrangement is 

 necessary, as, from the rapid motion of the tool, which makes GOO to 

 700 blows per minute, it would be impossible to introduce the work 

 without bruising it. A series of rests are placed opposite to each pair 

 of tools, which can be adjusted both in height and horizontal distance ; 

 the table carrying the rests can also be moved along the frame to 

 facilitate the adjustment. In using the machine, the swages are 

 adjusted So that, by placing the rod of iron successively between them, 

 it is drawn down to the size required, whilst the length of each part is 

 accurately ^determined by placing the end of the rod in the rest. The 

 machine cannot, therefore, turn out the work too small, whilst, at the 

 same time, it is so near the finished size, that very little has to be taken 

 off in the lathe. As an example of its economy over hand labor, it is 

 stated that a man with the machine will make 17 dozen spindles per 

 day, 15 inches long, and tapering from | to inch, at a rate, piece- 

 work, of 5d. per dozen, whilst by hand he could only turn out six 

 dozen, for which he Avould be paid lOd. per dozen. In some kinds of 

 work the economy is still greater. All kinds of files may, it is stated, 

 be forged by this machine at one third the cost of hand labor. Lon- 

 don Artisan. 



ON THE STRENGTH OF IKON EMPLOYED IN THE CONSTRUCTION OF IRON 



VESSELS. 



MR. "W. FAIRBAIRN, at the British Association, presented the results 

 of some experiments made by him, witli a view of obtaining same 

 knowledge of the strength of the iron generally used for the construe- 



