90 



NATURE 



[May 24, 19CX) 



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 pressures, 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 distinguished 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. 



add that in the present war it appears to have been handled in a 

 way worthy of the reputation of the corps. 



I fear^he causes of some of our military failures at the com- 

 mencement of the war must be looked for in other directions, 

 and the present unfortunate war will turn out to be a blessing in 

 disguise, if it should awaken the Empire to the necessity of 

 correcting serious defects in our organisation, possibly the natural 

 result of our constitution ; and, in that case, the invaluable lives 

 that have been lost will not have been sacrificed in vain. 

 { To be continued. ) 



THE USE OF STEEL IN SHIPBUILDING.^ 



lyr ANY changes and developments in the constructioti of ships 

 ^ *■ for the mercantile marine have taken place during the last 

 forty years. At the commencement of this period wood was 

 still the principal material employed for shipbuilding, and 

 although iron had been introduced for general shipbuilding 



31 3* 3S 





TRAVEL OF SHOT IN FEET. 

 Fig. 3. 



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 well aware that any practicable velocity or 

 energy they may desire for their guns is at their disposal. 



They have such guns, I mean guns with high velocity and 

 high energy — whether they have enough of them, and whether 

 they are always in the right place, is another matter, for which 

 perhaps the military authorities are not altogether responsible. 

 But velocity and energy is not the only thing that is required 

 under all circumstances in war, and I ask you to believe that if 

 the War Office authorities have, for their field guns, fixed on a 

 velocity yery much below what is possible, they have had sound 

 and sufficient reasons for so doing. 



My firm and I, individually, have had much to do with the 

 introduction of the larger high-velocity and quick-firing guns 

 into our own and other services; but as an old artillery officer, 

 in no way responsible for our field guns, I may perhaps be al- 

 lowed to say that, whether as regards materiel or personnel, 

 our field artillery is inferior to none anywhere ; and I. venture to 



NO. 1595. VOL. 62] 



purposes some twenty years earlier, the record of new tonnage 

 added to the British Register in i860 shows only about 30 per 

 cent, to have been built of iron. 



The general adoption of iron for shipbuilding on the Wear 

 dates from about the year 1863, and by 1880 it had, in that dis- 

 trict, entirely taken the place of wood. On the Clyde, Mersey 

 and Tyne, iron shipbuilding was adopted at an even earlier date. 

 So far back as 1855, iron had largely taken the place of wood 

 for shipbuilding on the Clyde. 



The difficulty of preventing the fouling of the bottoms of 

 iron ships due to corrosion or marine growths, and the conse- 

 quent loss of speed, led to various attempts being made to 

 sheath the bottoms of iron ships and cover the wood sheathing 

 with copper, yellow metal, or zinc sheets. The result was the 

 introduction of the system of construction known as "Compo- 

 site," in which the framing was of iron, with wood planking 

 wrought on the iron frames, and sheathed with copper or yellow 

 metal. 



1 Abstract of a paper read before the Institution of Naval Architects by 

 Mr. B. Martell. 



