involved in the Construction of Artillery. 



211 



136. In concluding this discussion of the relations of elasticity only, to the 

 materials for constructing artillery, it will be desirable to make clear the still 

 more important relations of ductility and ultimate strength upon which the 

 values of the coefficients of resistant vis viva of elasticity T^ and of rupture T 

 (already referred to) depend. 



137. The following Tables, iv. and v., give the results of the experiments 

 upon direct extension made by M. Ardantof the French Corp de Genie, and by 

 M. Bornet, for steel in its several conditions, harsh and ductile wrought-iron, and 

 hard and annealed brass ; and Table vi. the relation of elastic limit and exten- 

 sion, to ultimate cohesion : — 



Table IV. 



Experiments of M. Ardant on the Elongations per Metre in length of Wires, under Tensile Strains 



increasing vp to Rupture. 



The diameters of the wirea were from 0-40 to 1-60 millimetres, and the lengths from 1 to 1-5 metres. 



