CONTRIBUTIONS OF METALLURGY 259 



The Use of Cast Iron for Bursting Shells. With the steel 

 works representing more than 60 per cent, of the French steel 

 production overwhelmed by the first German onrush, the French 

 wisely adopted cast iron as one of the materials for their burst- 

 ing shells, thus releasing their small remaining steel produc- 

 tion for high-explosive shells, cannon, and other imperatively 

 needed ordnance. Fortunately, the manufacture of these cast 

 iron bursting shells had been developed at the Douai arsenal 

 before the war. 



Among the many advantages of this step were that the mak- 

 ing of these cast iron shells could be begun immediately at most 

 of the numberless iron foundries scattered all over the country; 

 that additional foundries for making them could be built far 

 faster than steel works could ; that the processes of production 

 are much simpler than the steel making processes chiefly be- 

 cause cast iron is very much more fusible than steel; that the 

 cast iron shells can be made from relatively impure and very 

 abundant raw materials, thus leaving the scanty supply of the 

 best materials for steel-making; that they are far cheaper 

 than steel shells ; and that their manufacture calls for far less 

 fuel. 



Ordnance engineers have been reluctant to use so brittle a 

 material for shells, lest they break in the gun and thus cause it 

 to burst. Even a thread left in- the barrel of a revolver in 

 cleaning it will lead to its bursting when next fired. But with 

 the Germans at the Marne it was imperative to increase the 

 shell production by all possible means, even if this led to the 

 occasional bursting of a gun. Better one gun crew in a hun- 

 dred blown to shreds then Paris taken. 



The risk of gun-bursting is probably less than it seems at 

 first, in view of the general use of cast iron in this country 

 for carwheels, even those of passenger coaches on express 

 trains, and of the insignificant number of the accidents caused 

 by breakages, in spite of the severe shock to each wheel on 

 passing each crossing at full speed. For that matter, cast 

 iron shells have been used very extensively here for target 



