490 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



vised for improving the method of manual puddling without 

 materially altering the existing machinery. One of these is 

 Dormoy's process of puddling with a rotating rabble, which 

 is thrown into rapid revolution by steam-power, while its di- 

 rection is readily controlled by the hand of the puddler. 



A revolving shaft above the furnace carries a belt which is 

 connected with another pulley below. This pulley is secured 

 to the outer end of the rabble, which is thus caused to rotate 

 somewhat in the fashion of the well-known revolving brush 

 used by the hair-dresser. By means of a handle jointed to 

 the lower pulley, the puddler readily directs the movements 

 of the rabble. From 300 to 500 revolutions per minute are 

 made by the tool when white pig iron is treated, and from 

 800 to 1000 for gray pig. The point of the rabble in the 

 furnace carries a disk which agitates the molten metal, and 

 effectually renews the surface exposed to the air. 



When the iron " comes to nature" another rabble is used, 

 having, in place of the disk, a short twisted point. Dormoy's 

 method has been successfully employed in Austria and France. 

 It is said that the yield of wrought iron is increased by at 

 least 30 per cent., while the consumption of fuel is propor- 

 tionately diminished ; that the puddler is relieved of much 

 of his fatigue, although the number of heats in a given time 

 is considerably increased ; and, finally, that the phosphorus 

 and sulphur are removed from the metal to such an extent 

 that excellent iron may be obtained from inferior brands of 



Pig- 



IMPROVED STEAM BOILER. 



Messrs. "Warsop & Eaton, of Nottingham, in England, have 

 lately constructed steam-boilers which, it is claimed, are not 

 liable to incrustation or explosion. It is asserted that water, 

 from which the air has been expelled, may acquire a temper- 

 ature far above 212 without boiling, and that it is then liable 

 to burst suddenly into steam -with explosive violence. This 

 danger is prevented by the process of these gentlemen, w T hich 

 consists in injecting heated air at a temperature of 650 near 

 the bottom of the water-space in the boiler, thus also aiding 

 in keeping up the supply of steam. All incrustation is said 

 to be prevented, and an economy of 15 per cent, of fuel ef- 

 fected. 15 A, August 10, 183. 



