January 25, 1900] 



NATURE 



301 



\merican manufacturers who require scientific as- 



ants appear to be perfectly satisfied with the edu- 



lon which is given to the students. In some of the 



^est works the heads of departments and designers are 



college graduates, and in not a few cases important 



111 responsible posts are reached at what seems to us 



a \ ery youthful age. Part of the success of American 



manufactures in outside markets is no doubt due to the 



-> >tematic and thorough technical training of those who 



(.li.iect their manufacture. 



The American student works harder than his English 

 confrere, and his work is mapped out for him along 

 strictly utilitarian lines ; for the average man the 

 American system is exceedingly good ; for the very good 

 man it is doubtful whether it is not too rigid, which may 

 explain why there are so few scholars and brilliant ex- 

 ponents of research produced in proportion to the large 

 number of students. F. W. Burstall. 



ARMOUR PLATES. 



THE different classes of armour which may be used 

 are as follows : — Wrought iron, steel, compound, 

 Harvey, and Krupp types. 



Wrought iron was largely used in the first armour-clad 

 battleships, and the late Sir John Brown was practically 

 the first manufacturer of them on a large scale in this 

 country. Owing to its toughness and freedom from 

 cracks under the impact from projectiles, this type held 

 its own for a long time ; it could be produced at a fairly 

 cheap rate, and was readily worked into shape. Although 

 attempts were made to employ steel long ago, owing to 

 the higher cost of this material and the methods of 

 fusion not being sufficiently perfected, until comparatively 

 recently, to enable mild or soft steel to be produced — 

 that is, steel low in carbon — this material did not make 

 much way until, in France, methods were introduced of 

 producing at one operation large masses of mild steel. 



In this country, however, we branched off into com- 

 pound plates — that is, plates composed of wrought iron 

 with hard steel faces. There is no doubt, however, that 

 the French policy was the better one, as mild steel plates, 

 though perhaps more easily perforated, do not crack under 

 impact to the same degree as compound plates. 



Owing, however, to the enterprise of the American, 

 Harvey, it was found possible to take soft steel plates 

 and carburise them in a similar manner to that which 

 has been used for centuries— that is, carburising by the 

 cementation process (though, of course, Harvey's treat- 

 ment was necessarily varied to suit the altered nature 

 of the material being treated), so that steel plates were 

 obtained with faces containing considerable percentages 

 of carbon, up to 70 or 'So per cent., whilst the rear 

 still retained its original soft and tough condition. 

 Such a plate, after being treated and quenched in water, 

 either wholly or on the hard side, then possessed a very 

 liard surface, against which a shot broke into fragments. 



F^urther improvements were introduced at Krupp's 

 Essen Works, both as regards the composition of the 

 r.teel used in the plates, a material being obtained of 

 tough nature, yet having great tensile strength with 

 liii(h elastic limit, and also a further improvement was 

 ettected by carburising the surface by means of gas 

 < ementation instead of charcoal. More regular and 

 uniform results have been thus obtained than by any 

 other process, and though by means of specially shaped 

 |tiojectiles, or projectiles fitted with soft metal caps, such 

 plates can be perforated, this is much more difficult than 

 formerly. Ordinary ogival projectiles without caps go to 

 pieces upon impact, their striking energy being wasted 

 in breaking themselves instead of perforating the plate 

 attacked. Briefly, it may be said that the latest type of 

 hard-faced plates possess about twice the resistance of 



NO. 1578, VOL. 61] 



the older type of plates. This enables a great saving to 

 be effected in the weight of armour to be used for the 

 protection of the modern warship. 



My firm has, however, recently produced capped 

 projectiles which, with a slightly higher velocity thart 

 the average usually employed, readily perforate hard-i 

 faced plates, so that before long we may expect 

 the latest type of plates to be found quite vulnerable. 

 Thus the battle proceeds, first the plate wins, then the 

 projectile, until perhaps some day all civilised nations 

 may find it more profitable to revert to a simpler and 

 more effective method of settling difficulties than by 

 trying to kill each other. R. A. H.\dfield. ' 



NOTES. 

 Expressions of opinion from political leaders as to the value 

 of scientific advice, and the need for scientific methods in 

 Government Departments, are so rare, that some remarks which 

 Lord Rosebery made upon this subject at Chatham on Tuesday 

 come almost as a surprise. We have over and over again re 

 ferred to the lack of interest in the progress of science, and the 

 disinclination to take advantage of available applications, shown 

 by official authorities concerned with national affairs. Only 

 recently some of the scientific lessons taught by the ^^ar have 

 been pointed out in these columns (pp. 37, 83), and some df 

 the services which a committee of men of science could render 

 to the Government if their advice were asked have been indi- 

 cated. From the subjoined extract from Lord Rosebery's 

 speech it will be seen that he is in accord with the methods 

 advocated in these columns. If the war leads to an acknow- 

 ledgment of the value of scientific opinion, the result will be 

 one upon which the nation may be sincerely congratulated. 

 The Times reports Lord Rosebery to have said : — *' We ought to 

 get another great advantage out of this war, for, after all, we in ' 

 this country have much to learn, and this war will have been a 

 cheap one, whatever it may cost, if it has made us learn several 

 important lessons. I humbly think that in this country we live 

 a great deal too much from hand to mouth. We do not proceed 

 by scientific methods. We go on the principle that things have, 

 carried on so well so far, that we are a noble nation, that we 

 are very rich, that we are pretty numerous, and that we have so 

 muddled out right in the end. But I say this, that we are a 

 people of enormous waste. We waste simply by not pursuing 

 scientific methods. I do not like to compare us with Germany. 

 It is hardly safe to mention the name of foreign Powers lest 

 some innuendo be suspected, or else some guilty thought in 

 one's mind. But at any rate we may be certain of this— taking 

 Germany as an example of the opposite method of treatment — 

 Germany is infinitely more painstaking and scientific in its 

 methods than we are. But, without taking as a model Germany 

 or any other country, I believe, if we wish to take full advantage 

 of the lessons of this war after it is concluded, we must become, 

 more scientific in our methods in commerce, in education, and 

 jn war. We are not methodical, we are not scientific, we are 

 not abreast of the more advanced nations of the day ; and if we 

 want to keep our place we shall have to consider the lessons we 

 have been taught in this respect. Depend upon it, however 

 brilliant you may be, the tortoise of investigation, method, and 

 preparation will always catch up and overtake the hare which 

 leaves everything to the inspiration and effort of the moment. 

 Great as the task before us in the field is at this moment, the 

 task that remains for us after this war is completed is the greatest 

 task that ever lay before a nation. You will have, when this 

 war is over, to put your Empire on a business footing. We' 

 must have no more discussions as to the way in whicli one thing 

 has happened to go wrong or has happened to go right. We 

 must consider, deliberately, patiently, and scientifically, the 

 methods by which we have been accustomed to proceed, and 



