CAST CAST-STEEL PLOUGHS. 337 



Very few, therefore, could be brought to a sufficient temper for 

 a good scouring plough, so that even if it conld stand the heat 

 to produce a proper temper, the warping would ruin the form, 

 so that the sections of the ploughs could not be duplicated, 

 which is requisite in order to supply 'new shares in place of 

 those broken or worn out. 



To remedy these defects, a most important invention was 

 made by Mr. F. F. Smith, of Illinois, in 1860, that of casting 

 ploughs from molten steel in iron moulds, a process which was 

 adopted by the Collins Manufacturing Company, of Collinsville, 

 Connecticut, the same year. It was a process of casting cast 

 steel, and hence the ploughs are known as cast cast-steel ploughs. 



THE COLLIKS PLOUGH. 



Being cast to form, they will keep that form after receiving 

 the highest temper. They can, therefore, easily be duplicated 

 from molten cast steel. This process forms a hardened cast 

 steel plough that the quartz sand, found in many prairie soils, 

 does not scratch. The sections receive their temper kindly, 

 because the metal is " set " in the iron moulds into which it 

 is poured, and where it has no strain upon its fibre. They do 

 not warp in heating or in cooling, so that the parts are dupli- 

 cated perfectly. A cast cast-steel plough has all the advantages 

 of cast iron, and hardened cast steel combined. 



The Collins plough, though a comparatively recent invention, 



has rapidly gained popularity and favor, especially on the prairie 



farms of the West. When tempered hard, it never clogs, but 



clears perfectly in sticky soils, and hence its draught is light 



43 



