Rab and his Friends

A subject that much interested Mr. Fairbairn during the best part of his life, and one on which he did most valuable service, was that of steam-boilers.

Iu his large practice as a manufacturer of steam-engines, he could not fail to see the extreme importance of that element of the machine from which its power was derived. He had his attention directed to the frequent occurrence of disastrous explosions ; and hence he was led to study carefully the mechanical principles involved in the construction and arrangement of boilers. He noticed many defects, and introduced several important improvements. He further made it his business to promulgate knowledge by writings and lectures on the structure and management of boilers ; and last, though not least, he founded a public association for the object of promoting safety in their use for manufacturing purposes generally.

Mr. Fairbairn began to make steam-engines soon after 1832, and the construction of the boilers for them formed an extensive manufacture in itself. In 1837 he applied to them his new invention of the riveting machine, as described in Chapter X.; and a few years later, viz., in 1844, he introduced a valuable change in boiler design.

lie was always an advocate for high-pressure steam, on account of its economical advantage but its use was limited by a fear of danger in the vessel wherein it was generated. The kind of boiler which had been found by experience to be best adapted for this purpose was that known as the Cornish or Trevithick's boiler. This was of cylindrical form, having a tube running through it in which the fire was placed, in the manner shown in the first of the following figures.

This had the disadvantage that the tube must necessarily be of large size, so as to admit sufficient fire, and it was on that account exposed to a severe external crushing strain, which its form was not well calculated to bear. It had also the evil that the water over the top of the tube was only of small depth, and that if by accident the water level happened to get low, the top of the tube, being exposed to the most intense action of the fire, was liable, to become overheated, which would lead to danger of explosion. The steam space was also contracted by the necessary height of the water line.

Mr. Fairbairn's improvement consisted in using two internal fire-tubes, of smaller size, instead of one large one. These tubes were subject to a much diminished external strain, while at the same time they allowed of an increase of the fire-grate and heating surface; and, what was of more importance, a much greater depth of water could be maintained over them, and the level could, if necessary, be lowered so as to enlarge the steam room. The second figure shows the improved arrangement.

The idea, though extremely simple, was admirably practical and useful; and the invention was patented by Win. Fairbairn and John Hetherington (an engineer who had aided hiin in it), on April 30, 1844 (No. 10,1(56).

This form of boiler found great favour. It was soon widely adopted, and is now by tar the most usual construction for high-pressure boilers in the manufacturing districts. Indeed, so common is it there that it is often called the ' Lancashire Boiler' in contradistinction to the ' Cornish ' one, which prevails in the south-western counties.

Independently, however, of his practice in the construction of boilers, Mr. Fairbairn had his attention called to them in another way, as it had been his lot to get many lamentable cases where either inattention to the proper principles of construction, or careless management, had caused disastrous explosions and fearful destruction of life and property.

The great extension of manufacturing industry in the Lancashire and Yorkshire towns had led to the employment of steam-power to a vast extent; steam-engines were required in great numbers, and their manufacture was often undertaken by persons not well instructed in scientific principles, and at prices which did not admit of all possible care being taken in regard to the proportions or the practical workmanship.

Moreover, these engines were not unfrequently worked under careless management, being put into the charge of incompetent or ignorant men, unable to see where danger arose, or unscrupulous as to overtaxing the powers of the apparatus. Hence, boiler explosions became but too common in these districts; and when they did occur, from the magnitude of the buildings and the great number of people employed, the consequences were usually very severe.

The worst feature of the case was that the causes of these explosions were often very difficult to trace out. The destruction was so complete that tangible evidence was iu a great measure destroyed; and it usually happened that the persons who would have been best able to throw light on the causes were killed. The proprietors or managers, not wishing to criminate themselves, were loth to admit that there had been anything amiss in construction or attention, and hence all sorts of fanciful theories were conjured up, such as electric action, chemical decomposition of the steam, and mysterious agencies of many kinds, to account for what was merely a natural sequence from simple mechanical conditions.

At the inquests held on such occasions the juries were often puzzled by these various theories, and it became a common custom for coroners or magistrates to call in an independent and impartial engineer to aid in the investigations, and to endeavour to throw light on the causes of the accidents.

Mr. Fairbairn, from his great experience and high reputation, was much iu request on these occasions, a few of which may be named.

In November 1815 he attended at Bolton, to examine into the circumstances of a disastrous explosion, by which fourteen lives were lost. He gave evidence at the inquest, pointing out defects in the boiler arrangements, and the jury returned a verdict of manslaughter against one of the partners, with a recommendation that Mr. Fairbairn's report 'should be forwarded to the Secretary of State for the Home Department, with a view of bringing the subject of steam-boilers before the legislature.'

In December 1850 he was called in by the magistrates of Halifax, to investigate a serious explosion that had taken place there, and which he succeeded in tracing to the weakness of a certain part of the boiler.

In November 1853 he attended at Blackburn, to give evidence on the bursting of a boiler at a mill im that town, by which seven persons were killed, and which he traced clearly to the defective condition of the boiler. He declined to receive remuneration for his sen-ices, directing that the fee offered him should be applied for the benefit of the families of the sufferers.

Many similar accidents were investigated by him, among which was the unfortunate explosion of a locomotive during its testing at the Atlas Locomotive Works of Messrs. Sharp, Roberts & Co., Manchester, in July 1858, by which nine persons were killed.

It was felt that it would be very useful both to the manufacturers and users of steam machinery if Mr. Fairbairn would make some publication of the knowledge he had gained on this subject, and at the beginning of 1851 he received the following letter :—

Lewis, January 11, 18.il.

My dear Sir,—It has occurred to the Committee of the Yorkshire Union of Mechanics' Institutes that you might confer an important lioou on the manufacturing classes of Yorkshire if you could deliver a lecture on 'Steam-Engine Boilers, the causes of explosion, and the means of prevention,' or something to that effect.

You have bestowed so much attention on the boiler explosion at Halifax, that we hope the preparation of the lecture would not be attended with much trouble.

That, and other similar calamities, would cause your lecture to be received with great interest. Our idea is that it should be a lecture expressly adapted to practical men, both to masters and engine tenters. We should ask the favour, if your numerous engagements would permit, of your delivering the lecture first to the Leeds Mechanics' Institution; and should say that you would lay the public under additional obligation if you could afterwards repeat the lecture in the Mechanics' Institutions of the three other great manufacturing towns of Yorkshire, Bradford, Halifax, and Huddersfield.

We feel that this is a very bold request to make, and we could not have made it had we not known your public spirit, and also that you are already fully charged with all the facts on the subject.

The report of the lecture in the papers would make it useful through the whole of Yorkshire and far beyond.

You are aware that the Earl of Carlisle has set a noble example by delivering two lectures to our Mechanics' Institution; but you do not need an example, as you have always been friendly to the diffusion of science and the advancement of the operative classes.

Requesting your kind consideration of our proposal, I am, dear sir, yours truly,

Edward Baikes,

President of the Yorkshire Union of Mechanics' Institutes.

Wm. Fairbairn, Esq.

He complied with this request, and on April 23rd and 24th he delivered two lectures before the Leeds Mechanics' Institution. In the first lecture, ' On the Construction of Boilers,' he discussed the forms, proportions, and material of such vessels, and the forces they were subject to ; in the second, ' On Boiler Explosions,' he explained the various probable causes of such accidents (giving many examples in illustration), and described various precautionary measures with the object of guarding against them. The lectures were repeated in several manufacturing town?, and were printed by the committee in the form of a cheap tract, 'in the hope that much practical benefit might result from their publication in that manufacturing district.' They were afterwards re-published in 'Useful Information for Engineers,' and in several foreign scientific periodicals.

At the meeting of the British Association at Hull, in September 1853, Mr. Fairbairn communicated a paper, entitled 'Experimental Researches to determine the Strength of Locomotive Boilers, and the causes which lead to explosion.' This was brought about by the bursting of a locomotive boiler belonging to the London and North-Western Railway at Manchester. Differences of opinion had arisen among engineers in regard to the causes of the failure of the boiler, and Mr. Fairbairn instituted a series of experiments fur the purpose of settling the question. They were directed to the resistance of locomotive boilers generally, and in particular to the strength of the screwed stays by which the internal fire-box is secured to the outer shell. A locomotive boiler was subjected to hydraulic pressure, increased till the boiler gave way, and it was inferred that it would bear 300 to 350 lbs. pressure per square inch before bursting. A trial was also made to determine the rate at which the pressure would rise, supposing the fire kept top and the safety-valve closed, and it was found that in about halt-an-hour a bursting force would be attained.

But, not satisfied with merely talking or writing about boiler explosions, the idea occurred to Mr. Fairbairn of doing something practical to prevent them, or at least to render them less frequent; and this idea led to the foundation by him of an ' Association for the Prevention of Steam Boiler Explosions,' which has been of incalculable benefit in the saving of life and property, and, in fact, has become, under his guidance, one of the most valuable mechanical institutions of the country. It is only due to him to give an account of the rise and progress of this excellent society.2

His notion was that, as he was convinced all boiler explosions arose from ordinary mechanical causes easily avoidable, it would be possible, by careful and frequent inspection or examination, to discover wdien anything was likely to go wrong, and so to apply a remedy in time. And he conceived that, by the formation of a society, this inspection might be made systematic, and might combine other advantages with that of safety.

It was about 1851 that he first gave expression to this idea. In his evidence with regard to a boiler explosion at Stockport, about April of that year, he said :—

It seems to me that there should be some association, either under the local authorities or under Government, by which registers should be kept, not only with reference to the safety of the public, but also to show what duty engines and boilers perform. The best results have arisen from such regulations in Cornwall, and it has led there to the greatest possible economy.

Further, at the Blackburn case in 1853, he again called attention to the subject:—

I think the inspection would be better in the hands of the proprietors of steam-engines, if they would undertake it, than in those of the Government. If the proprietors undertook the work it would have to be done under an Association of employers, and I have no doubt it would be much more acceptable to manufacturers that they should have the control of their own engines and boilers than that the Government should interfere.

The following extract of a letter shows that he had about this time been discussing the subject with his friends :—

Manchester, July 28, 1851.

Dear Sir,—The recent lamentable boiler explosion has recalled to my mind the subject of a conversation we had some time since, when we accidentally met in a railway carriage.

I think you then expressed the opinion that much would be done to prevent these catastrophes if owners of steam-engines couhl agree to retain the services of a suitable inspector, who should periodically examine and report upon the condition of the boilers and engines.

I hope that the importance of the subject will lead you to lay your views in some practical form liefore the public, and thus add one more to the many services you have already conferred upon it.

I remain, dear sir,

Your obedient servant,

Eichaen .Iohnsos.

Wm Fairbairn, Esq.

Mr. Fairbairn replied, and promptly gave attention to the matter. His first step was to find an influential manufacturer and mill-owner who would take an interest in the scheme; and he made a happy choice in Mr. Henry Houldsworth, the chief partner in a large firm of cotton spinners in Manchester. Some other gentlemen were spoken to, and a preliminary meeting was held on August 15; the general feeling was found to be favour able to the formation of such a society, and Mr. Fairbairn was deputed to sketch out its objects and rules, with the view of submitting them to a larger and more general meeting to be called for the purpose.

Meantime the attention of the public, was attracted to the proposal. A notice of the first meeting had appeared in the ' Manchester Guardian' of August 16, and the same paper, on September 16, devoted a leading article to a further explanation of the nature and objects of the proposed association, warmly recommending it to the attention of engineers and manufacturers.

The ' Mining Journal' of September 9,1851, recorded the verdict of the coroner's jury on a fearful boiler explosion at Eoehdale, which concluded with the following paragraph :—

The jury cannot separate without pressing on the consideration of the owners and users of steam-boilers throughout the kingdom the necessity there is that measures should be taken by them to ensure a thorough and frequent inspection of boilers, so as to prevent, as far as human foresight can, the recurrence of explosions.

In giving his evidence on this tragic case (where ten persons were blown to atoms and an immense deal of property was destroyed), Mr. Fairbairn

Suggested it was possible, and indeed quite practicable, to establish associations in the several districts, the members of which should appoint inspectors to take cognizance of the boilers within their respective precincts, and to report to the association weekly in what state they found them, and the causes which prevented them from being in working order, if the inspectors should consider such to be the ease. He did not conceive that it would be any tax on the proprietors of boilers to pay a trifling sum yearly to meet the expense of such an association, for it struck him forcibly that, in addition to preventing those very serious accidents, it would be productive of benefit to the proprietors themselves, and save a great deal of money.

The 'Journal' added:—

Since the above observations were written, we perceive that Mr. Fairbairn's earnest recommendation has been adopted, and that an association has been formed in the district for the inspection of steam-boilers and the prevention of boiler explosions. We cannot avoid anticipating from it the best results.

On the 19th of September a second meeting, convened by circular, was held in the Manchester Town Hall, the Mayor in the chair, when a committee was appointed for making arrangements for the formation of the association. They set vigorously to work, and for some time met every week, the minutes being usually signed either by William Fairbairn or Joseph Whitworth, or both.

They succeeded in enrolling 271 steam-users as members, and on Jan. 23*(1855, they called another public meeting at which the Society was formally established.

Mr. Houldsworth was the first president, but in April 1858, he retired, and Mr. Fairbairn was elected in his place, a position which he held tiil his death. He was ever one of the most active and persevering supporters of the association, always accessible to the chief engineer when seeking his advice, and always one of the most regular in his attendance at the meetings of the executive committee. He always advocated the view that steam-boiler explosions arose simply from a greater pressure of steam than the boiler was able to withstand, and never afforded any countenance to those fanciful and visionary theories that would have attributed them to mysterious causes. He maintained that periodical inspection was adequate to prevent the greater number of explosions, and he wished inspection to be the fundamental principle of safety.

The institution is now in a most flourishing condition. Its full title is, The Manchester Steam Users' Association, for the Prevention of Steam-boiler Explosions, and for the attainment of Economy in the Application of Steam.

Its objects and constitution are stated as follows:—

This association undertakes the periodical inspection of steam-boilers, and gives a pecuniary guarantee of the integrity and efficiency of its inspections to the amount of 300?. on each boiler enrolled, so that in the event of the explosion of an approved boiler, whether that explosion arise from collapse of the furnace tubes, or from rupture of the shell, or failure of any part of the boiler whatever, ail damage done thereby, other than by fire, whether to the boiler itself or to the surrounding property, will be made good to the extent of 300?.

The association also assists its members by taking indicator diagrams when requested, as well as by affording competent engineering advice with regard to the working of boilers and engines, the prevention of smoke, the economy of fuel, and any other points calculated to prove of value to the members of the association as steam-users.

Its system of inspection is voluntary, and permissive on the part of its members. Its reports are suggestive and recommendatory on the part of its officers. Its benefits are mutually-shared by all enrolled. There are no shareholders to whom dividends are paid out of the members' subscriptions, but the funds are devoted solely to promote the direct objects of the association. The executive committee are appointed by the general voice of the members of the association. They receive no remuneration for their services. They employ a considerable amount of steam-power themselves, and are thus interested in everything that affects its use.

The object of the guarantee is not so much to ensure the members against pecuniary loss in case of explosion, as to give a pledge of the bona fide intention of the association to prevent the occurrence of explosions by efficient supervision and careful periodical boiler inspection.

The number of members in 1874 was 768, and the annual income 5,236. The number of boilers under regular inspection was 2,689.

Soon after the foundation of the Boiler Association, Mr. Fairbairn determined to follow out one of the ideas which had been present to his mind when he established the society. It was originally his intention that the association, in addition to the commonplace work of inspecting boilers and finding out faulty or weak places, should undertake the investigation of theoretical principles. The practical views of his coadjutors were opposed to this, and it was struck out of the programme; but Mr. Fairbairn, nothing daunted, resolved to effect the investigations in his own way.

At the meeting of the British Association at Glasgow, in 1858, he urged the subject upon many scientific friends, and as the importance of it was admitted, it was agreed that the Koyal Society and the British Association should jointly authorise the enquiry, and should furnish a grant of money for the expenses.

The objects immediately named were to investigate certain doubtful points in the construction of boilers, and in the nature of steam. The former was first undertaken, and Mr. Fairbairn availed himself of the assistance of a practical mathematician, Mr. Thomas Tate (who had previously aided him in other labours) and Mr. Unwin, a young engineer, whom he had engaged as secretary.

The first result was a paper : On the Resistance of Tubes to Collapse,' read before the Royal Society May 20, 1858, and afterwards published in the Philosophical Transactions. It has already been mentioned that the internal tubes, or fire dues, of high pressure boilers, are subject to a severe external pressure, tending to cause them to collapse or crush in; in fact, they form the weakest and most dangerous element of the construction, inasmuch as the external crushing force is uncertain and obscure in its action, and the resistance to be provided against it is difficult to determine. When accidents have occurred with this kind of boiler, it is almost always the internal tube that has given way; ami some cases of collapse have occurred with a very moderate pressure.

No scientific or well-founded ride existed to guide the design or proportions of this part of a boiler, and hence it was desirable in the first place to make some experiments of a general nature to ascertain the resistance of tubes to strains acting in this way.

For this purpose, tubes of various dimensions, thick nesses, and lengths, were constructed, and were subjected, in a closed water bath, to external hydrostatic pressure till they collapsed, the pressures and the circumstances of collapse being carefully recorded.

The particulars were given in the paper, but the general result deduced from the whole was that the strength of the tubes diminished in an important degree as their length increased, a principle of much importance, on account of the great length steam-boilers were usually made.

It was always Mr. Fairbairn's principle to give, if he could, a practical value to his enquiries; and having discovered the defect, he set to work to find a remedy. It occurred to him that it would be possible effectively to shorten the tubes, without shortening the boiler. For this purpose he inserted stiff rings of iron at various points in the length, which served as supports to the tube in the places where they were fixed, so that the effective length of the tube was shortened to the distance between two of these rings. For example: in a boiler 24 feet long, by inserting two rings, the effective length of the tube became reduced from 24 feet to 8 feet, and the resistance to collapse was increased accordingly. He further suggested some improvements in the riveting, the advantages of which were described in the paper.

Mr. Fairbairn, in his Autobiography, thus alludes to this memoir:—

Shortly after the meeting of the British Association in Glasgow, I entered upon a long series of experiments on the law of the resistance of tubes to collapse. These investigations were the more interesting as they led to the establishment of the law of collapse from pressure on the external surfaces ; and the improvements deduced from this law led to the security of steam-boilers, by doubling or trebling their powers of resistance, and thus were the means of saving many valuable lives from violent death by explosion.

This was an important discovery, for ..in the case of steam-boilers with tubes it was found that the internal tubes were, in most cases, only one-third of the strength of the outer shell, and hence the fallacy of the ordinary belief, that the tubes from their reduced diameters were stronger than any other part of the boiler.

Another important feature iu these investigations was, that by simply encircling the tube with two or more rigid rings, the resistance to collapse was increased in the inverse ratio of the distances between the rings.

The experiments were very expensive, as large and powerful apparatus had to be prepared to sustain a pressure of upwards of 300 lbs. per square inch. In this I was assisted by a grant from the Royal Society, out of the Government fund, and I had every facility for conducting them at the engine shed of the Loudon and North Western Company at Longsight, .Manchester, who were interested in the subject.

This essay was one of the most meritorious works of Mr. Fairbairn's scientific and professional career, and deserves more credit than it has generally received. The process of investigation was admirably philosophical; there was first the ascertaining of facts by careful and well-directed experiment and observation; then there was the deduction from them, by scientific reasoning, of a general theoretical law"; and finally there was the invention and application of a measure founded on that law, which rendered the whole of practical utility and advantage. Mr. Fairbairn's anti-collapse flue rings, which arose out of this investigation, have been in constant use ever since, and have been the salvation of the high pressure stationary-engine boiler.

An abbreviated account of the investigation was published in the Report of the British Association for 1857.

On May 12, 1859, a second paper was read at the Royal Society, as a sequel to the former one, and in this Mr. Fairbairn connected Mr. Tate's name with his own.

It was entitled 'On the Resistance of Glass Globes and Cylinders to Collapse from Internal Pressure, and on the tensile and compressive Strength of various kinds of Glass,' and was published in the Philosophical Transactions for the year.

The novel results arising out of the first trials had suggested the propriety of carrying them farther, with a variation in the nature of the material; and glass was chosen, as a homogeneous crystalline and rigid substance, to contrast with the ductile and fibrous one at first employed. Moreover it was remarked that, much as glass was employed in philosophical experiments, there was a want of information as to its properties, which it was very desirable to supply.

Accordingly, the strength of glass to resist tensile and compressive forces was first experimented on ; after which trials were made on the power of glass vessels to resist external crushing force. The law of their strength was found to correspond with that deduced for iron tubes.

An anticipatory notice of this series of experiments was communicated to the British Association at their Leeds meeting, September 1858.

A third paper, which arose out of the boiler enquiry, was presented to the Eoyal Society on May 10, 1860. It w7as entitled 'Experimental Eesearches to determine the Density of Steam at Different Temperatures; and to determine the Law of Expansion of Superheated Steam, by William Fairbairn, Esq., F.E.S., and Thomas Tate, Esq.' This paper was considered of such importance and merit that it was selected by the Society as the ' Bakerian Lecture ' for the year, and it was published in the Phil. Trans., vol. cl.

The first object of the enquiry was to determine by direct experiment the law of the density and expansion of steam and other comlensible vapours at all temperatures. Theoretical laws had been propounded and extensively adopted, but no trustworthy direct experiments had been made to test their truth. The paper gave full details of a large number of carefully conducted observations made with this object, with a deduction of generalised formula: from the results obtained.

The second part of the paper was devoted to an investigation of the laws of what is called superheated steam. A plan had been coming into use, for steam-engines, of heating the steam after it had left the boiler, with the object of evaporating any water it might contain, and rendering it dry. This process, which was called superheating, was supposed to offer practical advantages, but no sufficient investigation had previously been made of the properties of steam so treated. The paper supplied, to a certain extent, this deficiency.

The authors were assisted by Mr. Unwin, and Mr. Fairbairn testified to the great precision and care with which the experiments were conducted. The substance of the enquiry was laid before the mechanical section of the British Association at their Aberdeen meeting in September 1859.

In this paper Mr. Fairbairn had occasion to refer to the great researches on vapours by the eminent French philosopher, Begnault. From the wide reputation of these researches and of their author, the following letter may be placed on record :—

Mon cher Mr. Fairbaim,—J'ai reju votre lettre, et je m'empresse d'y repondre par ecrit, afin de pouvoir vous l'envoyer de Paris, car lundi prochain je pars pour Londres, et j'espere bien que j'aurai 1'occasion de discuter oralement avec vous les questions importantes que vous avez traitees.

Vous pouvez faire l'usage que vous voudrez du tableau uumerique que je vous ai donne sur les forces elastiques des vapeurs. Grace au Ciel, le gros volume qui contient l'ensemble de mes experiences est enfin termine. Toici sept ans que l'im-j/rimeur a commence ; vous jugerez facilement que le volume represente une enorme labeur.

J'espere apporter ce volume moi-meme a la Societe Royale de Londres. 11 ne manque que la planche qui renferme les courbes grapliiques et qui n'est pas entidrement termine a la gravure.

J'aurai rhonneur de vous en offrir aussi un exemplaire quand le tirage sera termine.

Veuillez me croire

Votre serviteur devoue,

V. Ke(Jmault.

Some years before Mr. Fairbairn's death the question was much agitated whether it would be advisable to introduce any legislative measures to ensure the safety of boilers, or to prevent or diminish the danger of explosion. Mr. Fairbairn took much interest in the controversy. It seems that the matter had also excited interest in France, for in 1863 the eminent French mechanical engineer, M. Chas. Combes, wrote to ask Mr. Fairbairn's opinion, which was given as follows :—

Manchester: March 28, 1863.

My dear Sir,—In this country we are always jealous of Government interference, in matters relating to the industrial projects of individuals in their single or collective capacity, and that for two reasons ; firstly, that official inspection is not always judicious; and, secondly, that it removes the responsibility off the shoulders of those that ought to bear it.

I am quite aware of the regulations which exist in France as regards the construction of boilers, but in this country4we prefer that the owners of boilers should be responsible for their own actions, and the Government holds them responsible in every instance where loss of life or injury to the person arises from any neglect on their part. This is the extent of the English law, and every man is at liberty to make any description of boiler he pleases, but he must be answerable for the results. It is true, and we. admit it to be the duty of every Government to afford protection to life anil property, but not to interfere so as to cramp the energies and enterprise of individuals iu their pursuit of knowledge, and the advancement of industrial resources.

In this country, as in France, but at a later period, there was a transfer from the low-pressure system, as adopted by Watt, to that of high pressure, working the steam expansively, by which a considerable saving of fuel was effected. During the time of this change, which spread over a series of years, many serious accidents, attended with loss of life, occurred, and the public, in this district became alarmed to such a degree, that we found it necessary, in order to prevent Government interference, to establish the association of which I send you the rules. Being the founder of this association, I have never ceased to advocate its efficiency, and the principles on which it is founded. Out of an average of 1,600 boilers under the inspection of the association only three accidents, with the loss of two lives, have occurred during the eight years of its existence.

This association takes cognizance of the construction, form, and quality of material used, and the monthly reports point out, in every case, but without mentioning names, the defects that require attention, and of which a written statement is immediately forwarded to the proprietor, leaving it to his option to apply the remedies or not as he may deem expedient.

I have now to reply to your queries as follow, viz.:—

1. Is it desirable to fix by law, under penalty of fines, the thickness of plates, &c.

Answer.—It is not. desirable, as there is a great difference in the quality of plates. These points are left to the makers, and the association make no recommendations. They simply inspect existing boilers, and point out the defects, if any, and suggest the remedies to be applied.

2. Do you consider the previous testing necessary?

Answer.—We consider a hydraulic test necessary up to one and a half times, or in some cases to double the pressure at which the boiler is worked.

3. (Question not quoted.)

4. Is it desirable, to prescribe, under penalty of fine, the combustion of smoke?

Answer.—Yes, under local acts applied to towns, as the emission of smoke from furnaces may he prevented.

5. Are there any rules in England respecting the condition of the boiler house, &c.?

Answer.—There is no condition by law, but it is desirable in every case to have boilers in a separate building, distinct from the factory where a number of persons are employed.

Yours faithfully,

William Fairbairn.

M. Charits Combfs, Member of the Institute.

A little later the subject was taken up at the British Association, who, at their meeting at Norwich in 1868, appointed a committee, consisting of Messrs. Fairbairn, Whitworth, Penn, Hick, Bramwell, Webster, Fletcher, and others, to consider ' how far coroners' inquisitions are satisfactory tribunals for the investigation of boiler explosions, and how these tribunals may be improved.' The committee reported at the Exeter meeting in 1869, to the general effect that the inquests were unsatisfactory, and with a recommendation that coroners should get the assistance of skilled engineers. The report alluded to the fact that during the past session a bill had been introduced into Parliament for placing all steam-boilers under Government inspection; but the committee expressed a strong dread of any such legislative interference, iu which the meeting of the Association concurred.

The next year, 1870, the bill was re-introduced, when Sir William personally exerted himself to procure its rejection, and to obtain instead the appointment of a select committee to investigate the question. His efforts were successful, and the committee was appointed on May 16.

They sat many days, and took evidence, but could not conclude their labours, and adjourned over the recess.

In the meantime the committee of the British Association, at their meeting at Liverpool in 1870, took up the matter again, and presented a long report, the gist of which was in the last paragraph .—

Tliey are convinced that explosion might be, and ought to be, prevented; that competent inspection is adequate for the purpose; and that any well organised system of inspection extended throughout the entire country would partially extinguish boiler explosions.

But they did not point out what was the best means of ensuring this inspection.

The House of Commons Committee met again in March 1871, and took more evidence; but Sir Win. Fairbairn, conceiving that some of this was misleading, at once wrote an energetic letter to Mr. John Hick, the chairman, pro testing against it, and showing its fallacy. The committee reported in June, but their report did not go farther than to recommend that the responsibility of explosion should remain upon the steam users ; and that the efficiency of coroners' enquiries should be somewhat improved.

This left the question just where it was, and Sir WjI iiam had the gratification of seeing that, although his favourite remedy of inspection had not received Parliamentary confirmation, he had at any rate succeeded in defeating the attempt to introduce Government interference.

In April 1871 he published an article in the ' Quarterly Journal of Science,' embodying his views on this subject.

Sir William, in his late years, again exercised his invention on the subject of boilers. In 1870 he took out a patent (March 18, Xo. 810) for improvements in them, lie had long held the opinion that it would he advantageous to use a still higher pressure of steam. It had already been much increased in locomotives, and he believed it might be also increased with benefit in stationary engines, if the boilers could be made strong enough to bear the requisite strain with safety. He had, in his two hued boiler with the stiffening rings, added greatly to the strength; but still, when

any great power was required, it was necessary to have the outside shell of a large diameter, which always involved more or less danger, the risk being proportionate to the size. lie strove, therefore, to contrive a form of boiler which, while retaining ample heating surface and evaporating power, should enable him materially to reduce the diameter of the vessels used ; and the arrangement he hit upon was to substitute three or more smaller vessels for one large one. He placed the lire or furnace tubes within external shells, not much larger than themselves (thus leaving merely annular water spaces round them) and he added above them other vessels for the purpose of obtaining the requisite water and steam room ; proper communication pipes being made to connect the various vessels together. The annexed figure will illustrate the nature of the new construction.

By this means he could make, lie stated, boilers which would have a resistance equal to 75U lbs. pressure per square inch. He also added arrangements by which the examination, cleaning, and repair of the boilers might be much facilitated, knowing how much the safety and economy of working depended on these precautious.

In 1873 he took out another patent (January 23, No. 270), in conjunction with Mr. Thos. Beeley, a boiler-maker at Hyde, near Manchester, for improvements in the 1870 form of boiler, wliich rendered it more especially suitable for steam vessels; and in February 1874, he sent to the Admiralty a design for the adaptation of the new boiler to one of Her Majesty's frigates, the ' Paring.'

At the beginning of 1871, a few months before his death, lie expressed a wish to resign the chairmanship of the Boiler Association ; receiving the following letter in reply from one of his colleagues :—

Oroby Ltd, Ashton-under-Lyne, Maxell 10, 1874.

My dear Sir William,—Your letter of resignation was reaii at our meeting to-day, and there was evoked one united response expressive uf the feelings which in every heart arose on the reading of it. A resolution was promptly adopted, which will be sent to you officially. It conveys a very inadequate and imperfect recognition of the honour and esteem in which you

are held by your colleagues. We cannot let you break your official connection with us yet. So long in the Almighty is pleased to spare your valuable life, I earnestly hope we may have the great honour of your presidency. Your name and high character are a tower of strength to the Association of which you are the founder. Your services can never be realised. You have been the instrument of paving very many valuable lives by means of the Association. Allow us to continue to receive the lustre of your great name. For your sake we will do our best to uphold the reputation of the society. I feel it a very great honour to have been associated with you. May the years of your declining life be blessed with every mercy.

"With great respect, I remain,

My dear Sir William, yours sincerely,

Hugh Mason.

Sir William Fairbairn, Bart.

The last letter he wrote on engineering matters was one dated June 8, 1874, to Mr. Fletcher, the engineer of the Association, referring to a proposed test of one of his new boilers by hydraulic pressure up to the bursting point. The Association had a facsimile taken and distributed, as a memorial of their respected founder; a copy is inserted on the opposite page.

Mr. Fletcher has favoured the editor with the following remarks on the subject of boiler explosions, which, in consideration of the importance of this subject, and the great interest Sir William Fairbairn took in it, may be inserted here.

Manchester, July 5, 1878.

Dear Sir,—In addition to the information already furnished with regard to the Manchester Steam Users' Association, it may perhaps be of further assistance if I add a few lines thereto.

When the association first started its operation', a good deal of mystery was attached to the subject of steam boiler explosions, and they were apt to be attributed to very recondite causes. The association has been at the expense, however, of investigating the cause of every boiler explosion which has occurred for many years in any part of the country, cavefully recording the results, and circulating amongst the members and the public generally, by means of its printed monthly reports, an abridged account of the cause of each of these catastrophes.

The association has always advocated the view that explosions are not mysterious and not accidental, but that they arise from simple causes, the cause being, in the great majority of cases, merely that the boiler is too weak for the pressure at which it is worked, the weakness in some cases resulting from original malconstruction, such as the want of encircling hoops round the flues, &c., and in others from wear and tear, wasting of the thickness of the plate by corrosion, &c. All our investigations go to support the simple statement of the late Joshua Field, when President of the Institute of Civil Engineers, viz., that ' boilers burst because they are not strong enough.' That we lind to be the whole secret. The association does not take credit to itself for having arrived at this conclusion, but it has endeavoured persistently to keep this view before the public, and those not brought face to face with the circumstances of the case will scarcely believe how difficult it is to get this view-accepted after an explosion has occurred. The boiler owner and the boiler maker have both an interest in throwing the blame on the attendant, so that they always attempt to show that the explosion was due to shortness of water, through the attendant's failing to keep up the regular supply. In some cases the most absurd and fanciful theories have been suggested to account for explosions. They have been attributed to the formation of gases inside the boiler, ignited by the fire outside through cracks in the plates. In some cases they have been attributed to a sudden accession of pressure through the mixture of two steams flowing from different boilers. They have been sometimes attributed to magnetism or, in fact, to any cause but unscientific construction or the bad condition of the boiler. In Cornwall we find it most difficult to induce boiler owners to strengthen the furnace tubes with hoops. They cannot be persuaded that a boiler can burst unless short of water.

Sir William Fairbairn and the members of the executive committee, as steam users, always entertained a very wholesome dread of Governmental interference with private industries, and therefore hoped, by taking up the system of periodical boiler inspection, to render Governmental inspection unnecessary, so that they had in view a double object—one, to prevent the sacrifice of life by steam-boiler explosions; the other, to prevent Governmental interference, which it vias feared this loss of life would provoke. It is interesting to trace how the working of the association for years has somewhat led to a modification of the view with regard to Governmental interference, and this is a point to which I would call attention. It was found that, in spite of all the association could do, steam users still persisted in working old and dangerous boilers, and continued year after year to incur on an average fifty explosions, killing between sixty and seventy persons, and injuring about 100 others. Seeing that inspection was competent to prevent these disasters, the association felt at length compelled to urge on the Government to interfere in the interest of the public safety, and to take some measures to stimulate steam users to a due sense of their responsibility. What the association recommends is that the Government should institute an impartial and thoroughly competent tribunal to make a most searching investigation in the event of every explosion, so as to bring the blame home to the right party, the tribunal being empowered to institute a prosecution. The association has twice waited on the Home Secretary with memorials to this effect; the first time in June, 1875, and the second in June, 1876. The deputation was favourably received on each occasion (the memorials are published in our proceedings). Prior to this, the association had presented a memorial to the Home Secretary, in April, 1869, very much to the same effect as those referred to, the primary difference being that in the memorial of 1869 we proposed that the investigation should be conducted by the coroner's court, aided by scientific assessors, and in the memorials of 1875-76 it was to be conducted by another and more competent court, entirely independent of the coroner's.

Between the presentation of the memorial of 1869 and the one of 1875, public opinion seemed to set in favour of a direct compulsory system of enforced inspection, and Mr. Henry B. Sheridan, then member for Dudley, brought in a Bill for placing all the boilers in the country under the inspection of the Board of Trade. To this measure the association strongly objected, and instigated the appointment of a Select Committee to enquire into the whole question of steam-boiler explosions. Evidence was given before the committee by Sir William Fairbairn, by Mr. Hugh Mason, our present president, by the late Mr. Charles F. Beyer, member of our executive committee, and by myself.

The association has now fallen back from any system of compulsory inspection of boilers when in use, to a searching investigation of boilers after explosion, with a view of increasing the owner's responsibility. The question, like many others, has assumed different phases in different stages.

I have troubled you with this little history of the association's movement with regard to steam-boiler legislation, as it seems to me to open a very interesting and important question, and one that is being raised with reference to the conduct of other of the world's industries, such as mining, shipping, &c., the problem being how to control the careless without hampering the careful, and how to save human life and check recklessness without hampering progress. That questions of such interest should spring out of the simple subject of boiler inspection might not perhaps at first be anticipated.

We have at these offices very full illustrated reports of all the explosions the association has investigated, and which form a most valuable record.

Lavinston E. Fletcher, Chief Engineer.