4-O2 THE SCIENTIFIC PAPERS OF 



In the discussion of the Paper 



"ON THE CONSTRUCTION OF HEAVY ORDNANCE/ 

 By JAMES ATKINSON LONGKIDGE, M. Inst. C.E., 



DR. SIEMENS * said the author complained, and with some 



reason, that on the occasion of the reading of his previous paper, 



nineteen years ago, the discussion had wandered away a good deal 



from the lines laid down by him. The present paper presented 



such clear lines that it was not difficult to keep within them, and 



he would endeavour to do so. The paper might be divided into 



two parts. The first was the critical, and, he might say, destructive 



part, because the criticisms were such that, if completely borne 



out, one would almost be afraid to contemplate the result of a 



general war. The second part was suggestive or constructive. 



With reference to the criticisms on the Woolwich system, he was 



ready to admit that the author was very clear in his mathematical 



deductions. He had pointed out some error in one of the formulae 



used at Woolwich. Passing that over, he thought that the formulas 



which were used those of Professor Barlow and Dr. Hart were 



not erroneous in themselves ; but, as the author had shown, were 



insufficient to meet the case of the strain in every portion of the 



structure. The author had from that drawn the conclusion, that 



in not following out a formula, such as he had presented, the 



authorities had gone altogether wrong, that the strains by 



shrinkage which were applied at Woolwich were totally opposed 



to theory, and that much better results might be obtained in 



strictly following out the dictates of mathematical reasoning. 



Mathematics, however good a handmaiden, might be a very 



dangerous master ; and he thought he could show where the 



author had made mathematics his master. He had given his idea 



of a gun constructed on the Woolwich principle a 9 -inch gun. 



There was a steel tube of 8 inches thickness of side, around which 



he shrank iron to a thickness of 28 inches, with a shrinkage 



exceeding that usually given at Woolwich, namely, of 1 in 1,000. 



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

 LVI. Session 1878-1879, pp. 207-212. 



