1880.J Sequel to the ' Thunderer' Qua Exjylosion. 311 



This samo cvidcnco was equally fatal to another class of sugges- 

 tions as to the cause of the explosion, namely that tlio wad had bccomo 

 canted in front of the j^rojeetile, which, on the gun being fired, had 

 passed over the wad and converted it into a wedge of such character 

 as to burst the gun. 



Reverting to the air S2)ace suggestion, the Committee in their 

 Report showed that even if air spaces had existed, the result would bo 

 to diminish the pressure of the powder generally, although in some 

 instances, and under particular circumstances, a local pressure might 

 be developed upon a narrow band of the circumference of the bore in 

 the neighbourhood of the base of the projectile. A pressure, however, 

 of this kind would not be such as to endanger the gun, having regard 

 to the limited area over which it would act, and to the fact that this 

 limited area, besides having its own inherent strength, would receive 

 aid from the metal both in its rear and in its front, that in the rear 

 being exposed to but a comparatively slight pressure, while that in the 

 front would be exposed to scarcely any pressure at all. 



Further, there had been the experiments on Sir Wm. Palliser's gun 

 and the exjicriments by the Armstrong and Whitvvorth Committeo 

 made long ago, which had shown that air spaces were not sources 

 of danger to a gun. Moreover, at the time of the inquiry at Malta 

 we had before us the fact of an air space of 4 feet having existed in 

 the 100-ton gun on the occasion of one of the trials at Spezzia ; and 

 by the time I had delivered my last lecture, we had had, as I showed 

 by the diagrams, experiments made by Captain Noble on a 10-inch 

 gun chambered to 12 inches. In these last experiments the air spaces 

 varied from 2 feet to 6 feet. The general result was the lowering of 

 the pressure, but with the special result, however, when Rifle Large- 

 grain powder was used in lieu of the Pebble powder, of generating the 

 local pressure which I have said may be produced under certain 

 circumstances. All these experiments show that, whether the local 

 pressure was generated or whether it was not, the gun was uninjured. 



Other suggested causes of the explosion were, that the gun was 

 unfitted for ordinary use, because the materials were bad, or that it 

 had been injured by previous firing. 



The Committee, as you may remember, reported, for good reasons, 

 as it ajjpears to me, against all the preceding suggestions, and for 

 equally good reasons — ^he best of all reasons — the evidence afforded 

 by the fragments of the gun itself — gave it as their unanimous convic- 

 tion, that the explosion had resulted from the gun being fii'cd while 

 two charges were in it. 



This judgment of the Committee, I am glad to say, commended 

 itself at the time to many of those who were in possession of the 

 whole of the facts and who duly considered and weighed them ; but 

 we now know that a large number of professional men, well acquainted 

 with the practice of gunnery generally, but not taking the pains to 

 inquire into the special circumstances attending upon the working 

 of the gun in the fore turret of the ' Thunderer,' wore opposed to 



