300 ^Ir- Mallet on the Physical Conditions 



vantage of giving facilities for the absorption of recoil by means of elastic mate- 

 rial, pressed upon by the breech of the gun, instead of by the crude expedient 

 of mere mass in the gun itself, and thus would permit portability in the guns, 

 and lightness in the carriages, more especially of garrison guns, and other less 

 obvious advantages, not otherwise attainable. This method of dispensing with 

 trunnions, and still permitting elevation and depression of the gun with facility, 

 was actually carried out, with great mechanical skill, in the ancient Serpentine 

 described in Note A. 



303. To recapitulate : — The advantages, then, which the method now pro- 

 posed offers, for the construction of built-up artillery, of wrought-iron, are, as 

 respects the material itself : — 



1°. The iron constituting the integrant parts, is all in moderate-sized, 

 straight, prismatic pieces, formed of rolled bars only ; hence, with 

 its fibre all longitudinal, perfectly uniform, and its extensibility 

 the greatest possible, and in the same direction in which it is to 

 be strained; it is, therefore, a better material than any forged iron 

 can by possibility be made. 

 2". The limitation of manufacture of the iron, thus, to rolling, and the 

 dispensing with all massive forgings, insures absolute soundness 

 and uniformity of properties in the material. 

 3°. The limited size of each integrant part, and the mode of preparation 

 and combination, afibrd unavoidable tests of soundness and of 

 perfect workmanship, step by step, for every portion of the whole ; 

 unknown or wilfully concealed defects are impossible. 

 4°. Facilitj' of execution by ordinary tools, and under easily obtained 

 conditions, and without the necessity either for peculiarly skilled 

 labour, on the part of " heavy forgemen," or for steam or other 

 hammers, &c., of unusual power and very doubtful utility ; and 

 hence, very considerable reduction in cost, as compared with 

 wrought-iron artillery forged in mass. 

 5°. Facility of transport by reduction of weight, as compared with solid 

 gims of the same or of any other known material. 

 304. And, as respects the mode of application, — 



6°. A better material than massive forged iron is much more scientifi- 



