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which did nothing towards resisting the bursting strain of the 

 gun. This was a great drawback to that mode of construction. 

 Tin- amount of metal which actually resisted the bursting strain 

 was probably not more than one-third of the total weight of the 

 gun, the other two-thirds being used for a totally different 

 purpose to resist recoil and longitudinal action. Why should a 

 wire coil be used ? "Was metal in the form of wire susceptible 

 under ordinary circumstances of bearing any greater resistance 

 than solid metal ? Certainly not. The same strain per inch 

 could be resisted by solid material. In the case of wire there was 

 certainly this advantage, that inasmuch as the iron of commerce 

 was a mixture, or concrete, of the metal iron and a glassy 

 substance called cinder, if that glassy substance were mixed in an 

 irregular way with the iron it would give no tensile strength at 

 all ; but inasmuch as the layers of glass were drawn out in a 

 longitudinal direction, they did less harm than they would do if 

 mixed promiscuously ; and for that reason wire gave a larger 

 resisting strain than solid metal. That, however, was not the 

 case with steel. Steel wire resisted no better than solid steel. 

 On the contrary, steel wire, while resisting no better per square 

 inch, would give less elongation than solid steel ; but the author 

 would say, " You cannot, with solid steel, distribute your strains 

 in the manner I tell you to do ; there ought to be more strain 

 near the outer layers, and less towards the inside of the gun." 

 But there again he thought the steel maker would not be at a 

 loss. If it was desired to distribute a compressive strain on the 

 inner surface of the ring and a tensile strain on the outer surface, 

 could that not be obtained in any other way than by cutting the 

 whole thing up into wire and winding it round, thereby losing all 

 the advantage of longitudinal resistance ? He thought it was 

 quite possible. If a cylindrical mass of steel were heated in a 

 furnace to redness, then, while the steel was in the furnace, a 

 cooling action applied inside say, a spray of water would 

 immediately cause a solid tube of what was called set or cold 

 metal to be formed inside the mass. The inner diameter would 

 remain the same, because it was governed by the general mass of 

 the tube. The metal would shrink, not in the direction of the 

 diameter, but in the direction of the thickness of the tube, which 

 thickness would become less. If the cooling action went on while 



