.S7A' WILLIAM SIEMENS, F.K.S. 299 



In tin' i/iacuiis-ion oft/if 



'ON THE CONSTRUCTION OF AltTILLERY, AND 

 OTHER VESSELS, TO RESIST GREAT INTERNAL 

 PRESSURE," by JAMES ATKINSON LONGIUI*;K, M.lfn.st.r. K., 



Mi:. ('. \V. SiKMKN'S* said, many years ago he had some slight 

 practical experience in the use of guns, and had watched, with 

 great interest, the progress which had since been made in their 

 construction. Addressing himself to the subject of the paper, it 

 had been objected, that a gun constructed upon the plan proposed 

 by the author, would not have sufficient longitudinal strength. It 

 had occurred to him, that the longitudinal strength of ths gun 

 might be much increased, if instead of winding wire upon it, it was 

 bound with corrugated bands of steel, put on spirally. He esti- 

 mated, that two-thirds of the whole tensile strength of these bands 

 would thus be made available for longitudinal strength. He pro- 

 posed, that the core of the gun should be turned with spiral 

 grooves, extending backward beyond the bore, and fitting the 

 longitudinal ribs, or corrugation of the strips. The strips should 

 be put on under varying tension, while the gun rotated in a bath 

 of solder, in order to unite the several layers. He thought the core 

 of the gun ought to be of equally hard and tough material, and he 

 had no doubt, that the most serviceable gun would be one made of 

 solid, but mild, cast steel, well solidified by hammering. Such 

 guns were manufactured by Mr. Krupp, of Essen. From a report 

 made to the Prussian Government by Colonel Orges, it appeared, 

 that the German cast-steel gun had given the most satisfactory 

 results, as regarded strength. A bar of 1 inch square of this 

 material had borne a weight of 50 tons, whereas a bar of wrought 

 iron of the same dimensions broke with .88 tons. Mr. Krupp's 

 gun bore five and a half times the internal pressure of an ordinary 

 cast-iron gun of the same internal and external diameters, and 

 three times the internal pressure which burst a bronze cylinder of 

 the same dimensions. Mr. Krupp was now making three hundred 



* Excerpt Minutes of Proceedings of the Institution of Civil Engineers, Vol. 

 XIX. Session 1859-60, pp. 378-380. 



