December 21, 1893J 



NA TURE 



175 



lay buried, which could be dug up when numbers of the 

 experiments were compared. 



Meantime the condemnation of Admiral Beechey's law 

 by Parliament had put those concerned on devising a 

 substitute. Discussions over the subject went on from 

 August, i860, to January, 1862, but there is nowhere any 

 sign that the manoeuvring powers of the ships to be dealt 

 with ever came into view at all. A single diagram sur- 

 vi\es, which is reproduced in Fig. 4. It is obviously not 

 to scale, but was intended to show that a movement pro- 

 posed to be prescribed for one of the ships would be a 



-J^^ 



Fig. 3. 



dangerous one. It was not noticed that if scale were 

 applied to the diagram, it would show that no possible 

 movement on the part of either ship could avoid the 

 inevitable collision. 



The Rules of the Road of 1862 have been continually 

 modified since ; and by some appeal to experiment as 

 applied to diagram, the British delegates at the Washing- 

 ton Conference in 1889 were able to carry material 

 amendments. But the fallacy of the original basis has 

 been perhaps most forcibly brought out by Mr. John 



<^S> 



^ 



Fig. 4. 



<Glover before the Statistical Society in 1892. He showed 

 that while in the decade 1880-90, all other wrecks about 

 the coast of England have been reduced from 705 to 353 

 annually, the wrecks by collision have increased from 69 

 to 72 annually. 



The Rules of the Road — not yet superseded by those 

 ■of the Washington Conference — were once very carefully 

 attacked by means of experiment and diagram to scale. 

 The answer, made by the highest authority at the time, 

 was based on the diagram reproduced in Fig. 5. The 

 point was, what action No. i,when steering at different 



NO. 1260. VOL. 49] 



angles across No. 2's path, ought to take to avoid hei« 

 The diagram is again clearly not to scale ; but if scale be 

 applied, it is seen that No. i is always so placed that no 

 steps taken by her could possibly avoid collision. 



In 1865 I had the honour to be entrusted by the Ad- 

 miralty with the task of designing a system of mancjcuvring 

 iron-clad steam fleets to supersede that under which 

 Nelson had fought his battles, and which still remained 

 intact. I was enabled, by the kindness of the Admiral 

 commanding the Channel Fleet, to carry out a series of 

 experiments, incomplete no doubt, but sufficient for my 

 immediate purpose. The reduction of these experiments 

 to scale diagrams became the basis of a system of 

 manoeuvring which has scarcely been modified, though 

 it has been added to, down to the present day. The 

 flaw in it undoubtedly was the enforced assumption of 

 the circular arc, by the want of better methods of mea- 

 surement, and the fact that Boutakov's diagram repre- 

 sented general belief. 



The failure to duly connect helm-angle with the turn- 

 ing powers of the IVaritoi- now began to bear its fruit 



N9 2 



in a new direction. The present Sir Edward Reed, 

 K.C.B., became Chief Constructor of the Navy in 1863. 

 He was greatly impressed, as everyone then was, with 

 the necessity of good manoeuvring powers in men-of-war. 

 He connected had manoeuvring powers, as everyone 

 else then did, with length, and he was not impressed 

 more than anyone else was, with the desirability of 

 systematic experiment to ascertain what manoeuvring 

 powers really were, and what share different elements 

 had in influencing them. He proceeded, with universal 

 commendation, to reconstruct the Navy on the thesis 

 that a short ship was necessarily a better manoeuvrer than 

 a long ship. His Belleropho)i, only 300 feet long, was 

 laid down in 1864, and his Hercules — still regarded by 

 the whole Navy with affection— only 325 feet long, was 

 laid down in 1866. Sir Edward was justly proud of the 

 manoeuvring powers of the Bellerophoii, whose "dia- 

 meter" was only 401 yards, as compared with the 

 Warrior s 760. It was not sufficiently noted that the 

 smaller space was due in greater proportion to the 

 increase of helm-angle, by means of Captain Key's 



