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 University of California Berkeley 
 
 Gift of 
 GEORGE K. OPPENHEIM 
 
. 
 
 TECHNICAL EDUCATION 
 
 NAVAL ARCHITECTURE. 
 
 LECTURE 
 
 DELIVERED BEFORE THE 
 
 GREENOCK PHILOSOPHICAL SOCIETY, 
 
 JANUARY 19, 1883, 
 
 (The Anniversary of the Birth of James Watt,) 
 
 WILLIAM JOHN, ESQ. 
 
 LONDON : 
 
 PRINTED BY 
 
 SPOTTISWOODE & CO., 54 GRACECHURCH STREET, E.G. 
 
 1884. 
 
TECHNICAL EDUCATION 
 
 IN 
 
 NAVAL ARCHITECTURE, 
 
 Lecture delivered before the Greenock Philosophieal Society, 
 on January 19, 1883 (the Anniversary of the Birth of James Watt\ 
 
 BY WILLIAM JOHN, ESQ. 
 
 IT is extremely difficult for me to express to you the feeling I 
 have of the honour done to me, in inviting me to lecture to you 
 in this hall this evening. It is a compliment at any time to be 
 invited to address one's fellowmen, especially on a subject they 
 are well acquainted with ; and the whole surroundings of these 
 your Annual Meetings in memory of your great townsman, 
 James Watt, are of such a nature as to make it an honour 
 of which any man must necessarily feel proud. You have had 
 lectures here on these occasions from some of the most eminent 
 mechanicians who have in their day followed, with instruction, in 
 the footsteps of James Watt, and I am sure that even the most 
 celebrated among them must have felt, to some extent, the diffi- 
 dence I feel on the present occasion. 
 
 It is not for me to tell you anything about James Watt. His 
 name and his achievements are so blended with the traditions and 
 growth of your town, and every scrap of available information 
 respecting his wonderful career have been so carefully gathered 
 under the auspices of your society, and by his friends in this part of 
 the country, that any repetition of them here would be superfluous. 
 To you his memory is near and dear. To the whole country to 
 the whole civilized world, in fact his name is a household word ; 
 
and the world has probably been enriched more, and civilisation 
 advanced more, by the work of his brain than by that of any other 
 man who has ever lived. 
 
 I will say no more about the results of his work, but will glance 
 briefly at his method of work, as that is more intimately associated 
 with the subject of my lecture. 
 
 James Watt's life is the finest example I know of the value of 
 technical education in its true sense, by which, I mean, the com- 
 bination of scientific knowledge with practical skill. His successes 
 were not, as has been well said, a series of happy thoughts, or 
 flashes of genius, but were the result of careful and deliberate 
 thought and patient investigation, and this he had prepared 
 himself for by self-teaching and study, super-imposed upon a 
 sound early training. 
 
 Nothing could show the man and his method of work better 
 than the brief description given by Professor Rankine of what 
 immediately followed that great turning point in Watt's career 
 when he was engaged upon the repair of a small model of 
 Newcomen's engine at the University of Glasgow in 1763-4. 
 " The time " (as he puts it) " when science was to effect more 
 "in a few years than mere empirical progress had done in 
 " nineteen centuries. He perceived the various defects of that 
 " machine, and ascertained by experiment their causes. Watt set 
 " to work scientifically from the first. He studied the laws of the 
 " presence of elastic fluids, and of the evaporating action of heat, 
 " so far as they were known in his time ; he ascertained as accu- 
 " rately as he could, with the means of experimenting at his disposal, 
 " the expenditure of fuel in evaporating a given quantity of water, 
 " and the relations between the temperature, pressure, and volume 
 "of steam. Then reasoning from the data which he had thus 
 " obtained, he framed a body of principles expressing the con- 
 "ditions of the efficient and economic working of the steam 
 " engine, which are embodied in an invention described by him- 
 " self in the specification of his patent of 1769." 
 
 This reads so much like a simple record of common sense, 
 that we have to think for a moment of the centuries that had 
 elapsed before James Watt approached the subject in this way, 
 and the vast changes that have been wrought in the world in 
 consequence of his having done so, before we can fully realise the 
 work of his genius. But it is so with all the great discoveries that 
 have ever been made. Their simplicity, in after years, is food for 
 refreshing contemplation, and the periods of their first appearance 
 derive the healthiest form of excitement and mental stimulus. 
 
 To say nothing of the influence produced upon all the manu- 
 facturing industries of this country and the world by the improve- 
 ments which James Watt made in the steam engine, we may 
 for the present confine ourselves to his influence upon the 
 marine engine, and through the marine engine, upon the whole 
 
shipping, shipbuilding, and commerce of the country. No- 
 where has this been felt more than here in Greenock, Port 
 Glasgow, and the whole Clyde district. 
 
 The construction of steamers and their commercial success 
 followed almost immediately, as a matter of course, upon James 
 Watt's improvements of the steam engine, and it has gone on 
 since with tremendous strides up to the present time, when we 
 are building at the rate of nearly a million tons of shipping 
 per year in this country alone. The contrast between the Greenock 
 of to-day and the Greenock of James Watt's day indeed, the 
 contrast of the whole Clyde district now, and then is almost 
 without parallel, and it bears eloquent testimony to the value of 
 James Watt's work. 
 
 My subject to-night, however, is more with naval architecture 
 than engineering. James Watt was not a ship-builder, but it is 
 pleasant to think that he was descended from a ship-carpenter, 
 who had raised himself to the highest position of respect in this 
 town. 
 
 There are not wanting many features of similarity between the 
 history and progress of the steam engine, and the history and 
 progress of naval architecture ; and it may be of some interest in 
 connection with my subject to glance at them. 
 
 Naval architecture is of older date than the steam engine, but 
 many of its true principles were not developed until after James 
 Watt had given the steam engine its great impetus. We have 
 records of steam being used to perform work as early as the time 
 of Hero of Alexandria, more than a century before the Christian 
 era. But, more than a century before that, the Egyptians had 
 built vessels nearly as large as the " City of Rome " and " Servia " 
 of the present day, to say nothing of the Scriptural records of the 
 Ark centuries before. I need not trace the slow progress of the 
 steam engine in the centuries that followed Hero's time. It is 
 enough to mention the French engineer Debaus, the Marquis of 
 Worcester, Saver}', Dennis Papin, in the seventeenth century 
 Newcomen, Humphry Potter, Smeaton and others later, up to the 
 time when James Watt took the matter in hand, a little after 
 the middle of the eighteenth century ; and from that time, by the 
 establishment by him of really sound principles, the way was made 
 clear for all who came after. 
 
 What knowledge of the laws of Flotation Noah had, we know 
 not. The discovery of the first law of notation is attributed to 
 Archimedes, about a century before we find any traces of the use 
 of steam for performing work. The story of his jumping out of 
 his bath and crying " Eureka " when it occurred to him that the 
 volume of displaced fluid is equal to the volume of the body 
 immersed in it, is known to all of you. In this form, it is not quite 
 the first law of flotation, which requires also that the weight of a 
 floating body is equal to the weight of the fluid displaced. This, 
 
however, is easily deduced, and I need not trouble you further 
 with it. 
 
 Archimedes' time was an interesting period in naval architecture : 
 for, as I have mentioned, the Egyptians were building enormous 
 floating structures ; and, not only the Egyptians, but the Syracusans, 
 the latter under the guidance of Archimedes. And they must have 
 known something about shipbuilding in those days before they 
 could have put together in wood, as they are reported to have 
 done, vessels of over 400 feet long, and nearly 60 feet beam. 
 Beyond the marvel of their construction in those days, what strikes 
 one most is the fact that they were practically useless, for want of 
 adequate means of propulsion. Here were the monster ships ; but 
 the first whisper of the means of propulsion that was to render 
 them useful in the future had not been heard. Here was the ship, 
 but not the engine. It is not the only time that the naval architect 
 has been before his time in the grandeur of his ideas, because the 
 engines of the day had not arrived at tint point of efficiency which 
 warranted the attempt. However, as in the present day, the bitter 
 lessons of experience seem to have been taken to heart, for these 
 monsters were not repeated through the centuries which followed 
 down to the present time. 
 
 We read of those huge ships being propelled by 4,000 rowers, 
 and carrying 3,000 soldiers, but how the 4,000 rowers were arranged 
 or could be practically arranged, is quite unknown, and is one of 
 the bones of contention over which Antiquarians have battled for 
 years. We look at the Pyramids and Monoliths of Egypt with 
 immense awe an 1 astonishment, but if we think of the masses of 
 timber that had to be put together, and the ironwork and bolts 
 that must have been necessary for the purpose of building the 
 huge ships of Ptolemy Philopater and Hiero, we have scarcely less 
 room for wonder. It is true the Egyptian ships are not supposed 
 to have left the Nile ; but the one with \vhich Archimedes' name is 
 associated actually made a voyage from Syracuse to Egypt. 
 Perhaps it was from doubt of ever getting her safely back again of 
 turning her to any useful account that Hiero conceived the happy 
 idea of presenting her to the Egyptian King ; but as we have no 
 record of this it would be uncharitable to press the supposition. 
 
 I have not time in this Lecture to trace naval architecture 
 through its various phases from the early Phcenecian days the 
 rowing galleys of the Mediterranean, and the sailing craft of 
 the Norseman, until we come down to the times when the 
 Governments of this country, Holland, France, and Spain, and 
 other European nations, could boast of fleets capable of taking 
 and keeping the sea, and when their movements were fairly under 
 control, although exclusively associated with sail power. Little is 
 recorded, or was perhaps known, about the actual laws which 
 governed the flotation and propulsion of ships in those days. 
 
 .It was thought a very cunning thing of Sir Anthony Deane, in 
 
the 1 6th century, to be able to foretell the draft of water of a ship 
 before she was launched. This is one of the landmarks in naval 
 architecture. The next great landmark is when Bouguer began to 
 investigate the conditions of the stability of ships, and discovered 
 the meta-centre. Up to this time it must have been a matter of 
 pure empiricism in constructing a ship to know whether 'she 
 would stand up or turn over. It seems almost incredible, when 
 we think of the huge vessels built, say by the Spaniards in the 
 time of the Armada, that even these elementary principles of 
 naval architecture had not been investigated and understood : 
 and it is not to be wondered at that when storms arose they 
 got scattered and wrecked in all directions. We have nothing 
 beyond general references to the disasters that used to occur, but 
 they doubtless have served, as disasters have in the present day, 
 to turn men's minds to a consideration of the subject. No James 
 Watt arose, however, to enlighten naval architects in those days. 
 A great period of scientific investigation, however, set in on the 
 Continent. Bouguer was the first to throw some light on the 
 subject : after him many distinguished Continental savans, in- 
 cluding Dupin, Euler, D'Alembert, Bossut, the distinguished 
 Spaniard Don Juan, and Chapman, the celebrated chief con- 
 structor to the Swedish navy, devoted their minds to it. The 
 most beautiful and comprehensive treatise ever written, even to 
 the present day, on the Geometry of Floating Bodies, was 
 produced by Dupin in the early part of the present century, and 
 it is one that ali students of naval architecture should read and 
 study carefully. With Bouguer and Dupin I should be disposed 
 to put Don Juan in the front rank of the pioneers of science in 
 naval architecture. After their writings there could be no excuse 
 for ignorance as to the conditions of stability of ships in still 
 water. 
 
 It is well known that during the great French war our own 
 constructors were far behind the constructors of the French navy, 
 and our own ships were far inferior to the French : and there can 
 be no doubt that this arose m a great measure from the superior 
 training and superior science that was brought to bear on the 
 subject in France. It was the bravery of our own seamen, not 
 the skill of our constructors, that pulled us through ; and we were 
 only too glad when we cap ured a French ship to copy her lines, 
 and build in accordance with her design. 
 
 It is one thing to work out mathematically the conditions of 
 stability, and it is quite another thing to apply them practically to 
 shipbuilding : and I must therefore not omit to mention the 
 important application of Stirling's or Atwood's rule for finding the 
 areas of plain surfaces bounded by curves, and for finding the 
 moment of inertia of these same surfaces. And again, in combin- 
 ing the results for plain surfaces, by a similar process to find the 
 volume of displacement, the position of the centre of buoyancy, 
 
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 the meta-centre and other important elements in ship design. 
 Attwood's formula for finding from the lines of a ship her statical 
 stability should be mentioned as the next step, and next to this 
 Canon Moseley's formula for the dynamical stability. 
 
 But after all this, we had not got one step beyond the mere still 
 water stage ; and except for comparatively small angles of heel, 
 there was little or no actual data in existence of the stability of the 
 vessels afloat. Much prejudice undoubtedly existed in this 
 country amoung practical men against what they termed theoretical 
 men, and controversy often ran high. Looking at it from this 
 distance of time, I cannot help thinking that the practical men 
 had- some reason on their side in their prejudices, for the 
 theoretical men certainly vastly over-rated the importance of their 
 learning. 
 
 I now come to the period which in my opinion has done for j 
 naval architecture something like what James Watt did for the 
 steam engine. Of course, in one sense there is this difference, 
 that James Watt cleared up the essential principles of the steam 
 engine at an early date of its manufacture, whereas shipbuilding 
 had assumed large and important proportions before the period to 
 which I now allude. As I have shown, the principles which 
 govern the flotation and stability of a ship in still water were 
 sufficiently understood ; but that is about all that can be said. 
 All that pertains to the behaviour of the ship at sea, in regard to 
 rolling and pitching, and in regard to the resistance she experienced 
 in moving through the water, were almost a blank. 
 
 The period I now refer to is that of the foundation of the 
 Institute of Naval Architects in London in 1860. It gradually led 
 to the bringing together of practical and scientific men interested 
 in naval architecture. It led also to the collection of facts and 
 statistics connected with the behaviour of ships, and to valuable 
 experiments being made, the results of which were embodied in 
 papers read before that Institution. And even of more importance 
 was the fact, that it incited such men as the late Mr. Froude, of 
 Torquay, and Professor Rankine, to devote their remarkable powers 
 of investigation and analysis to the elucidation of the great problems 
 which had entirely eluded the attempts of such great scientists as 
 Euler, D'Alembert, and others, in the last century. 
 
 Before touching upon their investigations I will briefly summarise 
 the extent of our knowledge at that period. On the question of 
 stability in still water, we had, as I have previously intimated, 
 arrived nearly as far as we have done at the present moment. 
 The displacement of a ship could be found as accurately as it can 
 be now. Also the meta-centric stability and the statical stability, 
 and the dynamical stability for finite angles of heel. The method 
 of heeling over in dock for the purpose of finding the position of 
 her centre of gravity could be done, and had been practised, but 
 not to a large extent. The effect on the stability and trim of 
 
the ship of moving weights in her was also practically within 
 reach. 
 
 Calculations for finding the position of the centre of effort of 
 the wind on the sails of the ship, and the centre of lateral resist- 
 ance were common enough. Certain theories were extant upon 
 the effect of the form of the ship near the water-line affecting her 
 behaviour in rolling and pitching, according to the inequality or 
 otherwise of the wedges of immersion and emersion. It was 
 sufficiently well known, as a fact, that if ships were too stiff that 
 is, if their weights were stowed too low they would have a 
 tendency to roll violently, as experience had shown to be the case 
 with vessels loaded with ore and other heavy weights low down : 
 and of course it was known that if the weights were too high the 
 ship would capsize. There was also in existence mathematical 
 formula for the time of rolling of ships in still water, which, 
 however, did not include the effect of the resistance of the water 
 round the ship opposed to the rolling. So far as the question of 
 speed was concerned, the matter was in a far more unsatisfactory 
 state. Numerous experiments had been made at varying 
 times by Colonel Beaufoy and others, and various theories had 
 been propounded, but the true principles of the subject were quite 
 unknown. This was brought home to me rather forcibly by an 
 incident which occurred to myself during my apprenticeship. A 
 yacht was being designed exactly on the lines of the celebrated 
 yacht "America," but considerably smaller; and I remember the 
 attempts that were being made to regulate the sail power by that 
 of the "America," so as to give an equally satisfactory boat in 
 point of speed for her size as her prototype had been. It was 
 easy enough to regulate the moment of sail to the stability in such 
 a way that the two yachts would be equally stiff under the same 
 pressure of wind, but I remember every one consulted in the 
 matter entirely breaking down in the attempt to prove what the 
 relative speed of the two yachts would be. Here surely was a 
 question simple enough, if the available science at that time had 
 been worth anything on the question of speeds and resistances. 
 Thanks to Mr. Froude, matters are very different now. The 
 question of the strength of the ships was at the same period 
 namely, twenty years ago also in an unsatisfactory condition, 
 although not to the same extent as resistance. Very little had 
 been done in the way of actual calculations to ascertain the 
 principal strains to which ships of various sizes were subjected 
 at sea. 
 
 The pages of the "Transactions of the Institution of Naval 
 Architects," extending over the last twenty-two years, are now 
 the most valuable records connected with the profession. Next 
 to them stand the "Transactions of the Institution of Scottish 
 Shipbuilders and Engineers." I am sure you, as Scotchmen, will 
 not think it invidious that I place the London Institution first, 
 
10 
 
 for in their pages are nearly the whole of the invaluable 
 investigations of Froude and Rankine, which, in itself, would 
 be enough to turn the scale. Their researches have made the 
 science of Naval Architecture something really worth study, and 
 I will briefly summarise them for the benefit of students wishing 
 to make their acquaintance. 
 
 In 1 86 1 Mr. Froude read his remarkable paper on the Rolling 
 of Ships among Waves, and the novelty of the premises from which 
 he started, together with the elaborate mathematical investigations 
 supported by the results of modern experiments, produced a 
 startling effect. His conclusions were not immediately accepted 
 by many, but a few grasped at once the immense importance of 
 Mr. Froude's theory, and lent it their support. Among these 
 were Professor Rankine and Mr. Grassland of the Admiralty. 
 Both read papers on the subject in the following year. Put briefly, 
 the differences between Mr. Froude's theory and the ideas which 
 previously prevailed, were that whereas former theories of the 
 effect of wave-motion on a ship either regarded the waves as 
 acting on the windward side of the ship, and giving her so many 
 blows tending to throw her over to leeward ; or, that the effect of 
 waves rising on one side of the ship increased the buoyancy on 
 that side, whereas the retiring wave on the other side of the ship 
 diminished the buoyancy on the leeside and so formed a couple 
 tending to heel her to leeward. This latter was perhaps the more 
 generally accepted theory. 
 
 Throughout the investigations on the views that had prevailed 
 previous to Mr. Froude's paper, there had been no thought that 
 the weight of the ship, or rather, the reaction of the ship upon the 
 water, would be other than in a vertical direction, and herein lay 
 the fallacy that Mr. Froude destroyed. He showed that a ship on 
 a series of ocean waves large in comparison with her own size, 
 would have a tendency always to place her masts at right angles to 
 the slope of the wave, instead of, as had been previously supposed, 
 having a tendency to keep her masts vertical. Mr. Froude pushed 
 the matter to its extremest limits, and showed that a small 
 pendulum suspended on a raft which followed the slope of the 
 waves as it rode over them would have a tendency not to hang 
 vertically except at the hollow and the crest, but to hang perpen- 
 dicularly to the slope of the wave. He showed this scientifically, 
 and he had also tested it experimentally, and from this as a basis 
 he was able to construct equations which would accurately trace 
 the rolling of a vessel broadside on to a regular series of ocean waves. 
 He also drew some remarkable deductions from his equations, 
 which he had also proved experimentally. The most important of 
 these, was that when the period of oscillation of a ship in still 
 water coincided with the wave-period, the ship would go on 
 increasing the extent of her rolling until she might be rolled 
 absolutely over, although the waves were by no means high or 
 
II 
 
 violent. He had constructed an apparatus by which he could set 
 waves moving to different periods, and by exposing a number of 
 small models to them, he could so alter the periods of the waves 
 as to set any particular models rolling violently, or even to capsize 
 them, while the others were comparatively undisturbed ; and by 
 changing the period of his waves that is, the time the wave takes 
 to travel from crest to crest he could restore these models to 
 comparative rest, and set others in violent motion. Mr. Crossland 
 and Professor Rankine the following year, arrived at equations 
 very similar to Mr. Froude, by entirely different processes, but all 
 based upon what had first seemed an improbable assumption, but 
 has since been shown to be an absolute fact, namely, that the 
 tendency of the vessel is to keep her masts square to the effective 
 wave surface, instead of upright. Mr. Froude had started upon 
 the assumption that the form of ocean-rolling waves, when acting 
 in regular series, was trochoidal, and almost immediately after both 
 he and Professor Rankine proved simultaneously, one before the 
 Institution of Naval Architects, and the other before the Royal 
 Society, that the trochoidal hypothesis satisfied all conditions of 
 wave motion. Mr. Froude's investigations had an immense effect 
 upon the construction of the ships of the Royal Navy, as it was 
 seen at once that the excessive rolling of the early ironclads was due, 
 not as it had been supposed to the top-weight of armour and guns 
 they carried, but really to the fact that they had excessive stability 
 and a short period of rolling rather than otherwise ; and the meta- 
 centric height of the ships afterwards designed was reduced from 
 4 or 5 feet to 3 feet, or even less, with marked effect upon the 
 behaviour of the vessels at sea, and upon the ease with which they 
 could fight their guns in heavy weather. Mr. Froude's theory 
 was attacked severely by many, who ridiculed the idea that by 
 diminishing the stability of a ship you could make her steady 
 at sea ; but it survived all such attacks. 
 
 The papers which appeared year after year, for a succession of 
 years, from the pens of Mr. Froude and Professor Rankine, 
 dealing in still further detail with the problems presented by a 
 ship at sea, form one of the most valuable series of investigations 
 ever laid before a professional society. Mr. Froude's paper had 
 proceeded on the assumption that a ship was free to roll in the 
 water without resistance from the surrounding water ; that she 
 was free, in fact, to obey the impulse of her own statical stability. 
 He had fully realised that this could never be so in practice, and 
 distinctly guarded himself on this point in his original paper : 
 and he next set to work to ascertain, by experiment and analysis, 
 the limits within which this resistance, which had been left out of 
 account, would remain ; and this gave rise to a new series of 
 papers which appeared periodically, and culminated with a dis- 
 covery by Mr. Froude of a source of resistance that tended 
 considerably to modify the rolling of ships, which had not been 
 
12 
 
 sufficiently realised, and which he termed the wave-making 
 function. By experiments with ships and models, first setting 
 them rolling from side to side and recording the diminution of 
 roll each time, he was able to get at a measure of the work 
 exerted by the ship on the water in rolling from different 
 angles, and to create what he termed the curve of extinction, 
 which really represented the full resistance a ship had to retard her 
 own rolling. This he found to be so great that it could not be 
 accounted for by the mere pressure on the dead wood, keel, and 
 other flat parts of the ship ; and he found that the work was 
 absorbed in the creation by the ship in rolling of a series of 
 waves which travelled away from her. He also devised apparatus 
 of the most delicate kind for recording on board of ships the 
 phases of their rolling, and for recording at the same time the 
 wave forms corresponding with it ; and his experiments for 
 the Admiralty, made practically on board some of the ships of 
 the Royal Navy, are of the most valuable kind. 
 
 Mr. Froude's further investigations showed him, in some types 
 of ships, where the resistance was very great, either produced by 
 the form of the ship itself, or by the addition of bilge keels, that 
 there would be no danger of capsizing, even if the ship met with 
 a series of waves of the same period as herself, and this enabled 
 him to ascertain to some extent what he termed the limits of 
 rolling. His experiments in this direction showed clearly that in 
 certain cases bilge keels were really very effective as preventives 
 against rolling, and could be used with the greatest advantage. 
 The writings of Mr. Froude and Professor Rankine on this 
 subject, and also on the resistance of ships and marine propulsion, 
 made the higher branches of Naval Architecture, as I have said, 
 really worth study, and added dignity to the profession. 
 
 More recent writers on the subject have done little else than 
 paraphrase their beautiful illustrations and expositions. One or 
 two French writers have pursued the matter since into somewhat 
 more elaborate investigations, but they have not added much of 
 practical value to the labours of the two great men who in this 
 country gave shape and form to the subject. These questions of 
 rolling at sea are perhaps of more immediate importance to the 
 ships of the Royal Navy than to those of the Mercantile Marine, 
 where the type grows up more gradually from one ship to another, 
 and where absolutely fresh departures are not so often made as in 
 the ships for the Royal Navy. 
 
 The next great branch of the subject, however, to which Mr. 
 Froude devoted himself, is of the utmost importance to the 
 Mercantile Marine, and excites the utmost interest, namely, the 
 speed question, and in this direction he has done far more good to 
 the Mercantile Marine than in the other, and his work in this 
 direction, is, perhaps, even more fully appreciated by many con- 
 
nected with the Mercantile Marine than by the Admiralty, for 
 whom most of his experiments were made. 
 
 Professor Rankine had developed what is now known as the 
 Stream Line Theory of the Motion of Water round a ship in the 
 work on Shipbuilding edited by himself. Starting from this 
 theory, Mr. Froude commenced his experimental investigations, 
 and he had not gone far before he discovered a law which is of 
 supreme importance -in fact, almost the keystone of modern 
 investigations. 
 
 I have mentioned the difficulty I had met with in the yacht 
 similar to the " America." Mr. Fronde's discovery cleared away 
 all difficulties of the kind for the future. He showed that a 
 relationship existed between vessels of the same form, but of 
 different sizes, and that this relationship was as follows : that there 
 were corresponding speeds for the two vessels which varied as the 
 square root of their lineal dimensions, and that at these corre- 
 sponding speeds the resistance was proportionate to the displace- 
 ment. This, if true and the reasoning appeared absolutely 
 sound was of the utmost importance, because, for the first time 
 in the history of Naval Architecture, it enabled any one with the 
 necessary skill and appliances to predict, from the resistance of a 
 model of a ship at certain speeds, what would be the resistance of a 
 full-sized ship at the corresponding speed. This latter was amply 
 verified by experiments in towing Her Majesty's ship "Grey- 
 hound," and comparing her resistance with the resistance of her 
 model ; and since that time it has been further verified by 
 comparing the results of measured mile trials with the predictions 
 made from experiments with models of the ships. Mr. Froude, 
 like James Watt, was a man who liked to clear the ground all 
 around him, and, therefore, as any comparisons made between 
 ships and models, or between painted iron ships and copper- 
 bottom wooden ships, &c., involved the question of skin friction, 
 he set to work with experiments on this branch of the subject. 
 
 The investigation of the amount of the Skin Friction of different 
 surfaces moving in water added another link to our knowledge of 
 resistances. In the meantime the Mercantile Marine had been by 
 no means indifferent to this question of speed, and the necessity 
 for accurate and trustworthy data in connection therewith. 
 
 Mr. William Denny, of Dumbarton, had started the system of 
 progressive trials, and was also followed in this direction by 
 Messrs. Napier, Inglis, and other Clyde builders ; and Mr. Froude, 
 using the data thus supplied, made other most important advances 
 in our knowledge, and analysing the different elements that go to 
 make up the gross propelling power exerted upon a ship at sea, 
 he was able to divide it with tolerable accuracy under its different 
 heads. Thanks to Mr. Froude and Professor Rankine, all ship- 
 builders now, if they chose to go to the trouble and expense of 
 trying every ship they turn out progressively on the measured mile, 
 
14 
 
 can accumulate data which is capable of being used with certainty 
 in predicting the speed of new ships. 
 
 I have mentioned more particularly the works of Mr. Fronde 
 and Professor Rankine on the subject of the rolling of ships, and 
 on the question of speed, because they have, in my opinion, done 
 in a great measure for naval architecture what James Watt did for 
 the steam engine, namely, lifted it out of a position of comparative 
 darkness into a position of comparative light. They were both 
 men of science, not naval architects. 
 
 However, it must not be supposed that naval architects have been 
 idle during the period of the last twenty years to which I have alluded. 
 The amount of actual and reliable data furnished by the naval 
 architects of the Royal Navy, and of the Mercantile Marine, to the 
 pages of the Institute of Naval Architects, and the Scottish ship- 
 builders and engineers, is invaluable. The results of experiments 
 made upon actual ships on speed, stability, rolling, and other 
 properties, and scientific investigations in the same direction, 
 together with investigations of strength and strains, are sufficient 
 to redeem the profession from the charge of indifference to science. 
 And what I want more particularly to impress upon those youn'4 
 men who are studying, or about to study naval architecture, is 
 that it is of the utmost importance to them to carefully study the 
 work that has been done during this period, and to make them- 
 selves, as early as possible, conversant with the lines of thought 
 that have operated in different directions up to the point at which 
 we have now arrived, so as to put themselves in a position to go 
 forward into new, and much-needed investigations, and so as to 
 enlarge the common stock of knowledge. 
 
 It is not many years ago since the first curve of stability was 
 ever calculated, or the first set of curves for showing the distribu- 
 tion of longitudinal strains in a ship ; and until these were made 
 for certain types of ships, the actual conditions of safety against 
 capsizing, and the actual margin of safety against breaking in two, 
 or being unduly strained, were purely matters of guess work. 
 Later on H. M.S. "Captain " emphasised the necessity for more 
 elaborate calculations of stability, and created quite a revolution 
 in the Admiralty practice in this respect. 
 
 The enormous number of merchants' ships lost at sea empha- 
 sised the necessity for such calculations on the part of the 
 Mercantile Marine ; and it is a customary thing now, or should be, 
 to ascertain by experiment, which can be done in an hour or two, 
 the position of the centre of gravity of every ship when light, before 
 she leaves the builder's hands, and to approximate to her con- 
 dition of stability, under certain probable conditions of her loading. 
 
 It is not that when a ship is built you can do much to improve 
 her one way or the other, if she is faulty in point of stability, but 
 you can warn the owners of possible danger and how to minimise 
 it, and what to a builder is of still more importance you have the 
 
sure means of gradually accumulating accurate data, which, as it 
 increases becomes more and more valuable, and enables you in 
 dealing with future similar types of ships to approximate very 
 readily and very closely to the conditions of their stability. In 
 fact, this inclining experiment should go hand in hand with the 
 progressive speed trials, and in many yards it has become a 
 common practice. 
 
 On the question of the strength of ships, builders hands are 
 more tied than they are upon any branch of naval architecture, 
 owing to the almost invariable necessity of the vessels being 
 classed, in which cases the scantlings are provided, not at the 
 instance of the builder, but by the requirements of the Register 
 Societies. This is a delicate point on which I do not care to 
 enlarge at present. All that builders can do is to afford as much 
 information as possible upon this subject, and by intelligent and 
 temperate discussion of the principles involved, and the results 
 of experience, to induce the Register Societies to keep moving 
 with the times, and to keep improving their rules in accordance 
 with the best teaching of experience and science. 
 
 Among those who have contributed to the advance? of naval 
 architecture during the last twenty years, I have only mentioned two, 
 who have passed away. One other that has passed away will occur 
 to the minds of you for he spent some of his earliest and best days 
 here that is Mr. John Scott Russell ; who has on a previous 
 occasion lectured to you here in honour of James Watt, of whom 
 I know, from many of his lectures which I have heard, he was 
 a great admirer. 
 
 If Mr. Scott Russell did not advance the science of Naval 
 Architecture so much as Mr. Froude and Professor Rankine, he 
 certainly did wonders in popularising it as a study, and set many 
 men thinking in directions that probably might have escaped 
 them. He was one of the earliest in the field in the investigations 
 of wave-motion, and of its effect upon the behaviour of ships, 
 and especially upon the question of speed ; and his observations 
 upon the rule which exists between the length of entrance and 
 run of a ship, and the sizes of the waves which travel with her, 
 are daily becoming more recognised and valued. 
 
 Many naval architects have contributed their shares to the 
 stock of information which has been given to the public during 
 the last twenty years, but I need not particularise them. 
 
 I have mentioned the loss of the " Captain " as having been the 
 means of considerably extending our knowledge of the conditions 
 of stability of ships at very large angles of heel. The loss of the 
 " Stuart Hahreman," the " Eurydice," and the " Atalanta," showed 
 the necessity of pushing investigations in this direction still further. 
 The loss of so many grain-laden ships necessarily led to further 
 investigations into the effect on the stability of ships, of the shifting 
 of cargo within them, and the best means of obviating it. The 
 
i6 
 
 further and continued losses of vessels of similar type, coal laden, 
 and also with general cargoes, led to the conditions of stability 
 being examined for vessels of that type, laden with homogeneous 
 cargoes. In this way the stock of information has been gradually 
 accumulating, and must sooner or later have a beneficial effect 
 upon the naval architecture of the country, and tend to reduce the 
 loss of life and property. 
 
 Then again, the series of dismasting casualties that occured in 
 rapid succession, one after the other, led to further investigations 
 under the auspices of the Committee of Lloyd's, upon the strains 
 which take place in masts and rigging under trying conditions at 
 sea. 
 
 Again, there is the question of the load-line, with all the various 
 phases it has gone through during the last few years, and the 
 various investigations and rules that have been published with a 
 view to bringing this question within something like reasonable 
 limits : and there are the changes that have taken place from time 
 to time in Lloyd's rules. All these are matters which furnish 
 extensive fields of enquiry for future students in naval architecture. 
 
 For rendering progress in this study at all easy, a sound and 
 pretty extensive knowledge of mathematics is an absolute necessity, 
 and this cannot be too strongly insisted upon. 
 
 Any young man who aspires to the higher branches of naval archi- 
 tecture, should, in the first place, -fix his mind upon mathematics, 
 and be prepared to work hard at it for some years ; and he can 
 well afford to devote all his time to this and to the practical 
 details of his professional work in the earlier days of his pro- 
 fessional life. 
 
 It is no doubt extremely difficult and up-hill work to get a good 
 mathematical training, combined with the application of it to pro- 
 fessional work, without properly organised teaching. 
 
 Several attempts, as you are doubtless aware, have been made 
 in this country to promote such systematic teaching in naval archi- 
 tecture. The last great step in this direction, and one for which I 
 can never be too thankful, was initiated by Mr. Scott Russell, who 
 read, in 1861 or 1862, a powerful and impressive paper upon the 
 absence of any such establishments in this country. He described 
 how the Government had on two occasions established schools in 
 naval architecture at Portsmouth, and how they were successively 
 shut up. He strongly contrasted the state of our own country at 
 the time of his writing with the state of affairs in France, and 
 instanced himself and others, who were under the necessity of 
 sending their sons abroad to get them a professional and technical 
 training as shipbuilders, although this was the greatest shipbuilding 
 country in the world. 
 
 His recommendations, backed up as they were by the Council 
 of the Institution of Naval Architects, and by the higher pro- 
 fessional officers of the Admiralty, led the Government to institute 
 
the School of Naval Architecture at South Kensington ; and to 
 save it to some extent from the caprice of successive First Lords 
 of the Admiralty, it was placed under the Science and Art Depart- 
 ment, where it continued until it was some years ago incorporated 
 as a portion of the Royal Naval College at Greenwich. 
 
 At the time I studied at that School, our winter months were 
 devoted principally to mathematics, to ship calculations and 
 design, and to lectures from Froude and Rankine, Scott Russell 
 and all the principal authorities on various branches of science, 
 bearing more or less directly upon the profession we were studying. 
 There were lessons in chemistry, metallurgy, physics, and 
 such like ; but the backbone of the whole course of study was 
 mathematics, and its application to naval architecture and design, 
 with the other subjects, as it were, thrown in as accessories. The 
 summer months were spent in the Dockyards at practical work 
 and drawing. The course at the Royal Naval College at the 
 present time is pretty much the same as it was then, except that 
 the Course of Lectures has been, as I think unwisely, confined 
 almost entirely to the teachers at the College. 
 
 It may be asked whether so much time could be usefully em- 
 ployed in scientific study by one who has to get his living in the 
 mere mtile shipyards of the country ? I think it could. The want is 
 keenly felt in many shipyards of young men capable of making 
 calculations of any kind in reference to ships, and they would 
 easily find employment on advantageous terms. Another proof 
 that the market for such young men is open, may be gathered 
 from the fact that out of the fellow students of my own at 
 Kensington, several hold good positions outside the Government 
 service ; and, in fact, out of the first three or four years' students, 
 less than one half remained in the Government service more 
 than a few years. 
 
 This showed a demand outside, and a discontent inside, the 
 Service. Instead, however, of removing the causes of discontent, 
 the Admiralty placed those who remained under a penalty of ^50 in 
 case they left ; and this not proving sufficient they increased the 
 bond to ^250, and this has been paid in a couple of cases, in 
 order to free themselves for outside employment. You will notice, 
 that these were all men trained in the Government dockyards, 
 where, I may mention, there have for years been organised systems 
 of dockyard schools, which were the means of imparting mathe- 
 matical training. 
 
 Up to a few years ago there was little or no trace of such 
 facilities for young men in the private shipyards of the country. 
 There is now an improvement, owing to the Science and Art Classes 
 which are being established about the country, and I am glad to 
 hear that in Greenock a Science Class has been started recently, 
 and I hope its success will be marked. 
 
i8 
 
 In the town of Barrow, with which I am associated, there will 
 also, I hope shortly, be a similar class formed. 
 
 I have had a few particulars taken from the Reports of the 
 Science and Art Department for the past six years, which will 
 show that these classes have taken a pretty firm hold in some 
 parts of the country. In the year 1876 there were 12 classes in 
 Naval Architecture with 97 students 
 
 In 1877 10 classes 198 students 
 1878 10 167 
 
 l8 79 I 3 I 5 I 
 
 1880 21 359 
 
 1881 19 279 
 
 1882 15 308 
 
 You will see that the growth in the number of students has been 
 considerable, although it will be seen that the number of students, 
 as well as of classes, has been some what fitful, the causes of 
 which, however, I have not had time to investigate. 
 
 I look to the time when these classes will do much more good 
 than they are doing now, and I hope they will receive every en- 
 couragement from the builders in the neighbourhood. 
 
 It is not, of course, to be expected that they can furnish so high 
 a training as a three years' course of study under distinguished 
 mathematical and professional teachers, but they will have done a 
 great work if they enable all the rising draughtsmen to understand 
 and apply the ordinary ship calculations, and if they induce here 
 and there some of the more competent and ambitious among 
 them to go through a still higher training. 
 
 I do not know whether you are all aware that the Royal Naval 
 College is open to students in the Mercantile Marine, or any private 
 students. There is an entrance examination which must be passed, 
 but without competition, for those who are able to afford to maintain 
 themselves during their three years' course, and pay the college fees, 
 viz. ^75 for the course, or ^30 each year. There are, moreover, 
 free studentships for those who pass up to a certain standard, and 
 the Government, as well as Lloyd's Register, have offered scholar- 
 ships of ^50 a year, each to be competed for by any students ; 
 so that there is a chance for any young men who have perseverance 
 and talent enough to obtain free studentships at the College with 
 ^"50 a year each for three years towards their maintenance. They 
 would have their summer months for work either in the Royal 
 Dockyards, or in private yards to which they might be able to get 
 access. 
 
 I suggested elsewhere that it would well become a neighbour- 
 hood such as this, and other ports interested so much in shipping, 
 to add still further to such inducements ; and where students are 
 successful in this way, perhaps to double the amount of the 
 scholarship by local aid. 
 
19 
 
 Perhaps even a better way of promoting emulation, would be 
 for the shipbuilders of the country to contribute to a common 
 fund for this purpose, for the wider the field of competition, the 
 higher the honour of succeeding, and although few only would 
 gain the prizes which would be sought for keenly in every district, 
 the effect would be to stimulate all the classes, and raise materially 
 the average standard of efficiency to the benefit of all. 
 
 The guarantees now exacted by shipowners are so stringent 
 that builders cannot afford to neglect any source of knowledge 
 that will add to their power of prediction, and therefore safety ; 
 and competition is so close that they cannot afford a lavish ex- 
 penditure of engine power, and therefore cost, to keep on the safe 
 side. And perhaps at no time have shipbuilders, as a body, 
 been more disposed to avail themselves of scientific assistance ; 
 and the need will increase rather than decrease. This should be 
 a strong inducement and encouragement to young men to 
 prepare themselves with all their might for their future professional 
 careers, and those who do so will be well repaid. Above all, 
 I would say, avoid what may be called " theoretical crotchets," 
 and endeavour to gain so thorough a grasp of the first principles 
 involved, that there will be no danger of being led away by 
 tempting fallacies, which are always abundant in naval archi- 
 tecture. 
 
 Facts are never at variance with true science, and it is the 
 honest and unprejudiced attempts to reconcile them that often 
 brings the best reward. 
 
 I have taken up much of your time I fear too much. My 
 object has been to sketch briefly the scope of "Technical Educa- 
 tion in Naval Architecture," rather than to dwell upon the detailed 
 steps to be followed in the class-room. If it will be the means of 
 helping to stimulate the students of your new class in Greenock, 
 and if it will induce builders to extend to them a helping hand, 
 it will have fulfilled its purpose. In conclusion, I have only to 
 thank you for the patience with which you have heard me in 
 performing a task which to me has been one of pride and 
 pleasure. 
 
 MEMO. Since this Lecture was delivered the munificence of 
 Mrs. John Elder in founding a Chair of Naval Architecture at 
 Glasgow University, the appointment of Professor Elgar to fill it, 
 and the steps taken by the University Authorities to promote 
 classes for the higher technical education of Naval Architects in 
 the Mercantile Marine have supplied the want indicated in this 
 Lecture more effectually than I could have hoped at the time of 
 its delivery. W. J. 
 
LONDON : 
 
 SPOTTISWOODE & CO., PRINTERS, 54 GRACECHURCH STREET, B.C. 
 AND NEW STR'EET SQUARE.