6i4 Journal of Agriculture, Victoria. [ii Sept., 1911. 



be exercised to prevent the bellows bursting. This can happen if blowing 

 be discontinued before the coal becomes thoroughly ignited. The pressure 

 of the atmosphere, acting on the hea\ y combustible gases, drives them back 

 into the bellows ; and, when they join with the air confined within, form an 

 explosive which becomes ignited by the fire and often results in the bellows 

 being blown open. To guard against this disaster, blowing should be con- 

 tinued until the coals directly above the nozzle of the tue-iron become 

 bright, when it may cease without any possibility of injury. A good safe- 

 guard is to loosen the coal with the poker occasionally whilst blowing, which 

 prevents it forming a crust, and allows a free passage for the air to pass 

 through. 



In quenching the fire, the same thing may happen if there be a good 

 body of fuel above the tue-iron. The action of the water on top of the 

 fuel causes the gases generated h\ fire and water to be forced into the 

 bellows. As a preventive, take the rake and clear the fire away to one 

 side, leaving the nozzle in view ; then throw on the water. 



Some Fundamental Principle.s. 



Previous to describing the process of making some useful article, it 

 might be as well to mention that, in order to achieve success in the art, 

 there are several fundamental principles that must be fully recognized. 

 The usual idea of the ordinary layman that a blacksmith is one who makes 

 iron red hot and hammers it into shape is only partly true ; and, if accepted 

 by any one and applied, failure and disappointment will be the outcome. 



Blacksmithing is undoubtedly a difficult trade to learn, which is due to 

 the fact that it requires originality, quickness of thought and action, de- 

 termination and sound judgment. To acquire proficiency one requires a 

 knowledge of mathematics, an intelligent understanding of the nature of the 

 metals used and the effect that heat and hammering have on them, and 

 long practice. 



It is not the intention to deal minutely with all the intricacies of the 

 trade or enter too far into detail, but rather to carefully select objects which, 

 whilst having a direct application to farm work, will at the same time 

 possess educational value which will enable one to apply the knowledge 

 so gained in the accomplishment of requirements other than tho.se dealt 

 with here. That it would be impossible to describe all the work likely to 

 be required by the farmer in connexion with the repair of all his imple- 

 ments will be recognized and admitted. It is, however, hoped that the 

 information given in these articles will have beneficial results. 



The materials used in blacksmithing are wrought-iron, mild steel, and 

 cast steel. 



Iron is used principally where welding is necessary, as in the case of 

 links of chain, hinges, bolts, &c. In its nature, iron is fibrous like timber. 

 The fibres run longitudinally. It can be bent, twisted, or punched, either 

 cold or hot; it can be welded simply by the application of heat and pres- 

 sure without the use of solder, fluxes, or glue, as in the case of other 

 metals or wood; and, at suitable temperatures, it can be beaten into any 

 conceivable shape without loss of strength. 



The effect of heat on iron is to soften it; and, when the temperature is 

 raised to 2,700 deg. Fahr., it becomes in a plastic or soft and sticky con- 

 dition, in which state it may be joined together. When the heat is in- 

 crea.sed to about 3,000 deg. it melts. 



In working iron, it is not always necessary to raise to the welding heat. 

 Such operations as punching, bending and twisting are performed whilst 



