Jan. lo, 1889] 



NATURE 



243 



integrator, and other mechanical devices for reducing the 

 labour of calculations made in a naval architect's office, 

 were extensively used; and the time required for such 

 work was reduced to a small fraction of that formerly 

 expended. The integrator was modified by its inventor 

 at Mr. Denny's suggestion, so as to be better fitted for 

 the special work of stability, and other, calculations ; 

 while, on the other hand, the integrator was used so as to 

 enable large simplifications to be effected in the systems 

 of calculation. The manner in which the mechanical 

 integrator was used in Mr. Denny's office to reduce the 

 time and labour involved by laborious calculations, and 

 to effect improvements in the methods of calculation 

 themselves, is well illustrated by one of Mr. Denny's 

 most valuable contributions to the science of naval archi- 

 tecture, which is contained in a paper on " Gross Curves 

 of Stability, their Uses, and a Method of constructing 

 them obviating the Necessity for the Usual Correction 

 for the Differences of the Wedges of Immersion and 

 Emersion." 



Mr. Denny, as was his custom throughout, gave a 

 practical direction to his work in connection with the 

 subject of stability, by preparing for each steamer built 

 by his firm general particulars of her technical qualities, 

 " such as dead-weight capability, speed and power, sta- 

 bility," and other matters of importance, for the guidance 

 of her owner and captain. 



Mr. Denny was one of the most prominent advocates 

 and pioneers of the recent change from iron to mild steel as 

 the material of a ship's construction. He\vas the builder of 

 the Rotomahana, the first mercantile ocean-going steamer 

 constructed of the new material — a vessel which soon 

 answered objections made to the use of steel by ground- 

 ing on a rocky bottom and proving its superiority over 

 iron when subjected to the roughest of treatment. Mr. 

 Denny showed, in a paper read before the Iron and Steel 

 Institute in 1881, that the extra cost of steel per ton would 

 be more than counterbalanced by savings effected in the 

 weight of structure, and by the additional weight of cargo 

 that could thus be carried. The truth of this view was 

 soon proved by the commercial results of the use of steel 

 ships. He was always a consistent advocate of the use 

 of steel, and a stout upholder of its merits against all 

 attacks ; and he often pointed out with great force 

 and truth that defects arising from faulty design or bad 

 work had been attributed to the material itself. Hence 

 he strongly urged the necessity for more careful study of 

 structural defects, and of what he called the " morbid 

 anatomy of ships." 



It is impossible, within the space at our disposal, to 

 deal thoroughly with, or even to notice all of, the many 

 subjects associated with Mr. Denny's name. He did 

 much to improve the structural details of design, and 

 to bring about the introduction of double bottoms into 

 mercantile steamers. He was always an able and close 

 critic of the rules by which Lloyd's surveyors are guided 

 in the survey of ships for classification, and of the manner 

 in which those rules are carried out. He proposed, in 

 1877, to frame new rules, by which the displacement of a 

 vessel would be the standard for regulating the thickness 

 of the plating and the sizes of the frames and other parts. 

 Mr. Denny's arguments were met with what, at the time, 

 may have been a sufficient answer, viz. that there were 



no fixed load-lines for ships, and therefore there was 

 no definite amount of displacement. This answer does 

 not now hold good, however, seeing that since the report 

 of the Load-line Committee, in 1885, full meanshave been 

 in operation for fixing the load-lines, and therefore the 

 displacements, of ships. But there still remains much to 

 be said, on both sides, about Mr. Denny's proposals. 



Mr. Denny did some very valuable work as a member 

 of the Load-line Committee, a description of which will 

 be found in Chapter IX. In that Committee ; at an inter- 

 view with the President of the Board of Trade in 1883 ; 

 in giving evidence before the Royal Commission on Loss 

 of Life at Sea in 1885 ; and on all other suitable occasions, 

 Mr. Denny advocated a reform of the Marine Department 

 of the Board of Trade, in the direction of forming a Board 

 whose members would have personal knowledge of the 

 subjects dealt with and the interests aftected by them, 

 and of strengthening the executive staff of that Depart- 

 ment by furnishing it with the best scientific assistance 

 that could be procured. 



The cause of technical education never had a stronger 

 supporter than Mr. Denny. He advocated it, and worked 

 in it, at all times and seasons. Everyone engaged in the 

 scientific teaching of naval architecture had his eager 

 encouragement and generous help. The writer owes 

 much to him for practical assistance of every kind in 

 connection with the commencement and carrying on of 

 the work of the Chair of Naval Architecture in Glasgow 

 University. Mr. Denny was always ready to apply the 

 resources of his establishment to the benefit of others 

 who were working in the cause he had at heart. He was 

 an ardent advocate of technical education for all who 

 were entering the shipbuilding profession. His own early 

 training was very thorough, and he qualified himself, as 

 the record of his work proves, to occupy the first rank 

 among naval architects. Yet we find him dissatisfied, 

 and saying in 1883 to one who consulted him as to 

 sending a son to the Royal Naval College, " None of 

 the rest of us [the exception referred to is his brother 

 Mr. Archibald Denny, who now ably fills his place at the 

 works] were at the College, and it will be a lifelong regret 

 to me that I missed its advantages. . . . The work of these 

 schools [of naval architecture] is the leaven which is 

 slowly but profoundly inspiring and changing the charac- 

 ter of our profession." The practical efforts made by 

 Mr. Denny himself among his own people to improve 

 their technical training are best described in his own 

 words. In 1883, he said : — 



" Our attempts at technical education in our shipyard 

 and engine-works consist of the following : — 



" (rt) Rules as to the admission, by examination, ot 

 apprentices and others into the shipyard offices. 



" {b) The same for our engine- works. 



" {c) Rules to the Awards Committee to guide them in 

 rewarding the workmen for inventions or improvements. 



"A similar scheme of awards has been begun in our 

 engine-works. 



" From these papers and the private information given 

 to you as to the awards made, you will observe that our 

 attempts to stimulate the intelligence of our employ^ 

 have developed in two forms, corresponding to the main 

 divisions of these employe's. First, by examination we 

 have tried to secure a supply of apprentices and others 

 for our offices elected by ability and steadiness, and with 

 some knowledge suitable for the careers before them. 



