336 Sir Andrew Nolle [March 23, 



curves on the diagram, you will see that the velocity of the former is 

 nearly twice as great as that of the latter, while its energy and 

 capacity for penetration is nearly four times as great. 



I need hardly remind most of you that in artillery matters it is 

 the energy developed, not the velocity alone, that is of vital import- 

 ance. I venture to insist upon this point, because so many of those 

 who desire to instruct the authorities write as if velocity were the 

 only point to be considered. In a given gun with a given charge, if 

 tbe weight of the shot, within reasonable limits, be made to vary, the 

 ballistic advantage is greatly on the side of the heavier shot, and for 

 three principal reasons : 



1. More energy is obtained from the explosive. 



2. Owing to the lower velocity, the resistance of the air is greatly 

 reduced. 



3. The heavier shot has greater capacity for overcoming the 

 reduced resistance. 



You will observe that on this velocity diagram, upon which I 

 have kept you so long a time, is shown, not only the travel of the 

 shot in feet, but the position of the plugs which gave the velocities. 

 Further, on the higher and lower curves, the observed velocities are 

 shown where it is possible to do so. Near the origin of motion the 

 points are so close that it is not possible to insert them without con- 

 fusing the diagram. 



At the risk of fatiguing you, I show, in Fig. III., curves showing 

 the pressure existing in the bore at all points, these pressures being 

 deduced from the curves of velocity. 



You will note the point to which I drew your attention with 

 regard to the powder called B.N. You will remember, that in the 

 early stages of motion it gave velocity to the shot much more rapidly 

 than did the other powders. You see the effect in the pressure curves, 

 the maximum being considerably higher than any of the other pres- 

 sures, while the pressure towards the muzzle is, on the other hand, 

 considerably below the average. 



I fear you may think I have kept you unnecessarily long with 

 these somewhat dry details, but I have had reasons for so doing. 



In the first place, I desire to demonstrate to you the enormous 

 advances which have been made in artillery by the introduction of 

 the new explosives, and which we in a great measure owe to the dis- 

 tinguished chemists and physicists who have occupied themselves with 

 these important questions. 



Secondly, I desire to show you that the explosive which has been 

 adopted by this country, and which we chiefly owe to the labours of 

 Sir F. Abel and Prof. Dewar, is in ballistic effect inferior to none 

 of its competitors. I might go further and say that it is decidedly 

 superior. 



Lastly, at a time when the efficiency of all our arms, and especially 

 our artillery, is a question which has been deeply agitating the 

 country, I may do some good by pointing out that the authorities are 



