1862.] and its Resistance to Projectiles at High Velocities, 499 



twice as great with a round-ended punch as with a flat-ended one. 

 This of course only approximately expresses the true law ; but it exhibits 

 a remarkable coincidence with the results obtained by ordnance at 

 Shoeburyness, and explains the difference which has been observed in 

 these experiments, more particularly in those instances where round 

 shot was discharged from smooth-bored guns at high velocities. To 

 show more clearly the dynamic effect or work done by the weight of 

 shot which struck some of the targets at different velocities, the follow- 

 ing results have been obtained. 



From the above, it will be observed, that the two last targets have 

 sustained in work done what would, if concentrated, be sufficient to 

 sink the largest vessel in the British navy. 



We are all acquainted with the appearances and physical character 

 of artillery, but few are conversant with the nature of the operations 

 and the effects produced by shot on the sides of a ship or on resisting 

 forts and targets. 



The shot of a gun — to use the expression of my colleague, Mr. 

 Pole — is simply the means of transferring mechanical power from one 

 place to another. The gunpowder in the gun developes by its com- 

 bustion a certain quantity of mechanical force, or work as it is now 

 called, and the object of the shot is to convey this work to a distance, 

 and apply it to an object supposed to be otherwise inaccessible. The 

 effect of this, according to ^Ir. Pole's formula, is — 



W = weight of the shot in lbs. 



V = ita velocity in feet per second. 



Then, by the principle of vis viva, the quantity of work stored up 

 by the moving mass, measured in lbs. one foot high, is — 



g being the force of gravity = 32^. 



Thus, if we have a shot, like that recently used against the * Warrior* 



