132 HORSE-SHOES, ETC. 



Fig. 84. Eacing plate iron, -f X ^ inch. Now little used, 

 having been superseded by steel. 



Cast Iron. — To effect a saving in cost many 

 Fig. 84.— Racing attempts have been made to introduce cast shoes. 



plate iron.' 



Up to the present no real success has been recorded, 

 although shoes have been produced which admit of being shaped 

 and punched at a red heat, if special precautions be observed. 

 Even the best cast shoes are extremely brittle both when hot and 

 cold, are difficult to ' fit out,' wear more rapidly than wrought 

 shoes, give a bad foothold, and expose the horse to the danger 

 of slipping. 



Steel is fairly ductile and malleable and possesses the power 

 of being * tempered,' in which condition it is harder and more 

 elastic, though more brittle, than before. Certain improve- 

 ments recently made .in the manufacture of steel seem to point, 

 however, to the possibility of using it more extensively, and the 

 Paris General Omnibus Company have now employed it for some 

 years both for front and hind shoes, to the exclusion of iron. In 

 France steel of the kind used costs less than iron. It is said 

 to wear with perfect regularity until the shoes are extremely thin. 

 The farriers like it, and can turn out per day a larger number 

 of shoes than with iron, but certain precautions are needful where 

 it is employed : the metal must not be overheated, suddenly 

 quenched, nor much worked, in this respect differing from iron, 

 which is improved by hammering. The present opinion in 

 England is that good iron is sufficiently durable, and that steel, 

 unless of a low grade, is too difficult to work, and becomes too 

 smooth in use, so that it gives no foothold; but this view deserves 

 reconsideration after the successful experiments in Paris. 



Aluminium, being one-third the weight of iron, has been 

 used with success for racing plates. When pure, it can even be 

 worked cold, but must then be free of silicon, which renders it 

 brittle. It should never be heated above a dull red. To 

 diminish wear of the shoe, steel nails, with soft shanks and 

 hardened heads, are used. Chrome aluminium, being very hard, 

 might perhaps be used with advantage. 



Aluminium bronze, composed of aluminium 90 parts, copper 

 10 parts, is harder than the pure metal, but must be heated, 

 being difficult to work cold. Shoes of this substance are there- 

 fore cast, but have not been found sufficiently durable. 



