THE ROYAL ARTILLERY INSTITUTION. 
817 
up; our experience has been gradually gained, but to Sir W. Armstrong 
cannot, I think, be denied the credit of being mainly instrumental in 
combining different principles and improving details, so as to produce an 
efficient method of manufacture for large ordnance. He has doubtless been 
ably assisted, both by his own partners and by his assistants in the Royal 
Gun Factory, but no one can blame him for accepting this assistance or for 
turning to account the many advantages of his position. In saying this, I 
do not mean to justify his appointment as Superintendent of the Royal Gun 
Factories, which it is now generally admitted was a mistake. 
The essential features of the Armstrong method of construction, are:— 
1st. The disposal of the fibre of the metal round the bore (by coiling), so 
as to resist the tangential strain, the welds running in the direction of least 
strain as regards their separation. 
2ndly. The employment of a breech piece, to support the bottom of the 
bore, with the fibre running lengthwise so as to resist longitudinal strain. 
3rdly. The shrinking on the different portions, so that the exterior of the 
gun takes a due share of the strain* 
The separation of the different parts of the guns now made is guarded 
against, not only by the tension of one part over another, but by means of 
shoulders and corresponding recesses (Figs. 2 and 3). 
Fig. 3. 
These and other details of manufacture, as the decreased diameter of the 
cascable in the later M.L. guns, the best form for the bottom of the bore, 
&c., will, I daresay, be fully explained by Mr Anderson, who I understand 
will give a Lecture here on the 26th of this month. Mr Anderson is, I 
believe, an advocate of a steel barrel with a closed end, and he will doubt¬ 
less give reasons for his preference. 
I will here remark on the vexed question of coiled iron for the inner tube 
of a gun. It is often asserted that a sound coiled iron tube cannot be made, 
and that it is folly to attempt to produce one. I must, however, beg to 
question this statement. Large numbers of coiled iron barrels have been 
made, and, notwithstanding slight flaws, have shewn great endurance. If 
flaws must occur, they are, in a well made tube, so small, and in such a 
direction, that they are practically of little importance, and do not usually 
enlarge to a dangerous extent before the gun is worn out.f The coiled iron 
Fig. 2. 
* As proposed by Captain Blakely (late R.A.) 
f Sir W. Armstrong pointed out, before a Committee of the House of Commons, the difference 
between the flaws in the welds of a coiled barrel and in those of a forged solid tube. He said: “ In 
the barrel which is forged solid, tho lines of the weld run longitudinally with the bore j now we not 
