Mr. Bessemer brought the subject of his invention before the meeting of the British Association at Cheltenham in the autumn of 1856. There he read his paper "On the Manufacture of Iron into Steel without Fuel."* [footnote… On the morning of the day on which the paper was to be read, Mr. Bessemer was sitting at breakfast at his hotel, when an ironmaster (to whom he was unknown) said, laughing, to a friend within his hearing, "Do you know that there is somebody come down from London to read us a paper on making steel from cast iron without fuel? Did you ever hear of such nonsense?" The title of the paper was perhaps a misnomer, but the correctness of the principles on which the pig iron was converted into malleable iron, as explained by the inventor, was generally recognised, and there seemed every reason to anticipate that the process would before long come into general use. …]
I was present on the occasion, and listened to his statement with mingled feelings of regret and enthusiasm—of regret, because I had been so clearly superseded and excelled in my performances; and of enthusiasm—because I could not but admire and honour the genius who had given so great an invention to the mechanical world. I immediately took the opportunity of giving my assent to the principles which he had propounded. My words were not reported at the time, nor was Mr. Bessemer's paper printed by the Association, perhaps because it was thought of so little importance but, on applying to Mr. (now Sir Henry) Bessemer, he was so kind as to give me the following as his recollection of the words which I used on the occasion.
"I shall ever feel grateful," says Sir Henry, "for the noble way in which you spoke at the meeting at Cheltenham of my invention. If I remember rightly, you held up a piece of my malleable iron, saying words to this effect: 'Here is a true British nugget! Here is a new process that promises to put an end to all puddling; and I may mention that at this moment there are puddling furnaces in successful operation where my patent hollow steam Rabbler is at work, producing iron of superior quality by the introduction of jets of steam in the puddling process. I do not, however, lay any claim to this invention of Mr. Bessemer; but I may fairly be entitled to say that I have advanced along the road on which he has travelled so many miles, and has effected such unexpected results that I do not hesitate to say that I may go home from this meeting and tear up my patent, for my process of puddling is assuredly superseded.'"
After giving an account of the true origin of his process, in which he had met with failures as well as successes, but at last recognised the decarburation of pig iron by atmospheric air, Sir Henry proceeds to say:
"I prepared to try another experiment, in a crucible having no hole the the bottom, but which was provided with an iron pipe put through a hole in the cover, and passing down nearly to the bottom of the crucible. The small lumps and grains of iron were packed around fit, so as nearly to fill the crucible. A blast of air was to be forced down the pipe so as to rise up among the pieces of granular iron and partially decarburise them. The pipe could then be withdrawn, and the fire urged until the metal with its coat of oxyde was fused, and cast steel thereby produced.
"While the blowing apparatus for this experiment was being fitted up, I was taken with one of those short but painful illnesses to which I was subject at that time. I was confined to my bed, and it was then that my mind, dwelling for hours together on the experiment about to be made, suggested that instead of trying to decarburise the granulated metal by forcing the air down the vertical pipe among the pieces of iron, the air would act much more energetically and more rapidly if I first melted the iron in the crucible, and forced the air down the pipe below the surface of the fluid metal, and thus burn out the carbon and silicum which it contained.
"This appeared so feasible, and in every way so great an improvement, that the experiment on the granular pieces was at once abandoned, and, as soon as I was well enough, I proceeded to try the experiment of forcing the air under the fluid metal. The result was marvellous. Complete decarburation was effected in half an hour. The heat produced was immense, but, unfortunately more than half the metal was blown out of the pot. This led to the use of pots with large hollow perforated covers, which effectually prevented the loss of metal. These experiments continued from January to October 1855. I have by me on the mantelpiece at this moment, a small piece of rolled bar iron which was rolled at Woolwich arsenal, and exhibited a year later at Cheltenham.
"I then applied for a patent, but before preparing my provisional specification (dated October 17, 1855), I searched for other patents to ascertain whether anything of the sort had been done before. I then found your patent for puddling with the steam rabble, and also Martin's patent for the use of steam in gutters while molten iron was being conveyed from the blast furnace to a finery, there to be refined in the ordinary way prior to puddling.
"I then tried steam in my cast steel process, alone, and also mixed with air. I found that it cooled the metal very much, and of itself could not be used, as it always produced solidification. I was nevertheless advised to claim the use of steam as well as air in my particular process (lest it might be used against me), at the same time disclaiming its employment for any purpose except in the production of fluid malleable iron or steel. And I have no doubt it is to this fact that I referred when speaking to you on the occasion you mention. I have deemed it best that the exact truth—so far as a short history can give it—should be given at once to you, who are so true and candid. Had it not been for you and Martin I should probably never have proposed the use of steam in my process, but the use of air came by degrees, just in the way I have described."
It was thoroughly consistent with Mr. Bessemer's kindly feelings towards me, that, after our meeting at Cheltenham, he made me an offer of one-third share of the value of his patent. This would have been another fortune to me. But I had already made money enough. I was just then taking down my signboard and leaving business. I did not need to plunge into any such tempting enterprise, and I therefore thankfully declined the offer.
Many long years of pleasant toil and exertion had done their work. A full momentum of prosperity had been given to my engineering business at Patricroft. My share in the financial results accumulated with accelerated rapidity to an amount far beyond my most sanguine hopes. But finding, from long continued and incessant mental efforts, that my nervous system was beginning to become shaken, especially in regard to an affection of the eyes, which in some respects damaged my sight, I thought the time had arrived for me to retire from commercial life.
Some of my friends advised me to "slack off," and not to retire entirely from Bridgewater Foundry. But to do so was not in my nature. I could not be indifferent to any concern in which I was engaged. I must give my mind and heart to it as before. I could not give half to leisure, and half to business. I therefore concluded that a final decision was necessary. Fortunately I possessed an abundant and various stock of hobbies. I held all these in reserve to fall back upon. They would furnish me with an almost inexhaustible source of healthy employment. They might give me occupation for mind and body as long as I lived. I bethought me of the lines of Burns:
"Wi' steady aim some Fortune chase;
Keen hope does ev'ry sinew brace;
Thro' fair, thro' foul, they urge the race,
And seize the prey:
Then cannie, in some cosy place,
They close the day."
It was no doubt a great sorrow for me and my dear wife to leave the
Home in which we had been so happy and prosperous for so many years.
It was a cosy little cottage at Patricroft. We had named it "Fireside."
It was small, but suitable for our requirements.
We never needed to enlarge it, for we had no children to accommodate.
It was within five minutes' walk of the Foundry, and I was scarcely
ever out of reach of the Fireside, where we were both so happy.
It had been sanctified by our united love for thirteen years.
It was surrounded by a nice garden, planted with trees and shrubs.
Though close to the Bridgewater Canal, and a busy manufacturing
population was not far off, the cottage was perfectly quiet.
It was in this garden, when I was arranging the telescope at night,
that I had been detected by the passing boatman as "The Patricroft Ghost"
When we were about to leave Patricroft, the Countess of Ellesmere, who, as well as the Earl, had always been our attached friends, wrote to my wife as follows: "I can well understand Mr. Nasmyth's satisfaction at the emancipation he looks forward to in December next. But I hope you do not expect us to share it! for what is so much natural pleasure to you is a sad loss and privation to us. I really don't know how we shall get on at Worsley without you. You have nevertheless my most sincere and hearty good wishes that the change may be as grateful to you both as anything in this world can be."
Yet we had to tear ourselves away from this abode of peace and happiness. I had given notice to my partner* [footnote… The "Partner" here referred to, was my excellent friend Henry Garnett, Esq., of Wyre Side, near Lancaster. He had been my sleeping partner or "Co." for nearly twenty years, and the most perfect harmony always existed between us. …] that it was my intention to retire from business at the end of 1856. The necessary arrangements were accordingly made for carrying on the business after my retirement. All was pleasantly and satisfactorily settled several months before I finally left; and the character and prosperity of the Bridgewater Foundry have been continued to the present day.
But where was I to turn to for a settled home? Many years before I had seen a charming picture by my brother Patrick of "A Cottage in Kent" It took such a hold of my memory and imagination that I never ceased to entertain the longing and ambition to possess such a cottage as a cosy place of refuge for the rest of my life. Accordingly, about six months before my final retirement, I accompanied my wife in a visit to the south. In the first place we made a careful selection from the advertisements in the Times of "desirable residences" in Kent. One in particular appeared very tempting. We set out to view it. It seemed to embody all the conditions that we had pictured in our imagination as necessary to fulfil the idea of our "Cottage in Kent." It had been the property of F. R. Lee, the Royal Academician. With a few alterations and additions it would entirely answer our purpose. So we bought the property.
I may mention that when I retired from business, and took out of it the fortune that had accumulated during my twenty-two years of assiduous attention and labour, I invested the bulk of it in Three per cent Consols. The rate of interest was not high, but it was nevertheless secure. High interest, as every one knows, means riskful security. I desired to have no anxiety about the source of my income, such as might hinder my enjoying the rest of my days in the active leisure which I desired. I had for some time before my retirement been investing in consols, which my dear wife termed "the true antibilious stock," and I have ever since had good reason to be satisfied with that safe and tranquillising investment. All who value the health-conserving influence of the absence of financial worry will agree with me that this antibilious stock is about the best.
The "Cottage in Kent" was beautiful, especially in its rural surroundings. The view from it was charming, and embodied all the attractive elements of happy-looking English scenery. The noble old forest trees of Penshurst Park were close alongside, and the grand old historic mansion of Penshurst Place was within a quarter of a mile's distance from our house. There were many other beautiful parks and country residences in our neighbourhood; the railway station, which was within thirty-five minutes' pleasant walk, enabling us to be within reach of London, with its innumerable attractions, in little more than an hour and a quarter. Six acres of garden-ground at first surrounded our cottage, but these were afterwards expanded to sixteen; and the whole was made beautiful by the planting of trees and shrubs over the grounds. In all this my wife and myself took the greatest delight.
[Image] Hammerfield, Penshurst.
From my hereditary regard for hammers—two broken hammer-shafts being the crest of our family for hundreds of years—I named the place Hammerfield; and so it remains to this day. The improvements and additions to the house and the grounds were considerable. A greenhouse was built, 120 feet long by 32 feet wide. Roomy apartments were added to the house. The trees and shrubs planted about the grounds were carefully selected. The coniferae class were my special favourites. I arranged them so that their natural variety of tints should form the most pleasing contrasts. In this respect I introduced the beech-tree with the happiest effect. It is bright green in spring, and in the autumn it retains its beautiful ruddy-tinted leaves until the end of winter, when they are again replaced by the new growth.
The warm tint of the beech contrasts beautifully with the bright green of the coniferae, especially of the Lawsoniania and the Douglassi— the latter being one of the finest accessions to our list of conifers. It is graceful in form, and perfectly hardy. I also interspersed with these several birch-trees, whose slender and graceful habit of growth forms so fine a contrast to the dense foliage of the conifers. To thus paint, as it were, with trees, is a high source of pleasure in gardening. Among my various enjoyments this has been about the greatest.
During the time that the alterations and enlargements were in progress we rented a house for six months at Sydenham, close to the beautiful grounds of the Crystal Palace. This was a most happy episode in our lives, for, besides the great attractions of the place, both inside and out, there were the admirable orchestral daily concerts, at which we were constant attendants. We had the pleasure of listening to the noble compositions of the great masters of music, the perfectly trained band being led by Herr Manns, who throws so much of his fine natural taste and enthusiastic spirit into the productions as to give them every possible charm.
From a very early period of my life I have derived the highest enjoyment from listening to music, especially to melody, which is to me the most pleasing form of composition. When I have the opportunity of listening to such kind of music, it yields me enjoyment that transcends all others. It suggests ideas, and brings vividly before the mind's eye scenes that move the imagination. This is, to me, the highest order of excellence in musical composition. I used long ago, and still continue, to whistle a bit, especially when engaged in some pleasant occupation. I can draw from my mental repository a vast number of airs and certain bits of compositions that I had once heard. I possess that important qualification for a musician—"a good ear;" and I always worked most successfully at a mechanical drawing when I was engaged in whistling some favourite air. The dual occupation of the brain had always the best results in the quick development of the constructive faculty. And even in circumstances where whistling is not allowed I can think airs, and enjoy them almost as much as when they are distinctly audible. This power of the brain, I am fain to believe, indicates the natural existence of the true musical faculty. But I had been so busy during the course of my life that I had never any opportunity of learning the practical use of any musical instrument. And here I must leave this interesting subject.
So soon as I was in due possession of my house, I had speedily transported thither all my art treasures—my telescopes, my home stock of tools, the instruments of my own construction, made from the very beginning of my career as a mechanic, and associated with the most interesting and active parts of my life. I lovingly treasured them, and gave them an honoured place in the workshop which I added to my residence. There they are now, and I often spend a busy and delightful hour in handling my tools. It is curious how the mere sight of such objects brings back to the memory bygone incidents and recollections. Friends long dead seem to start up while looking at them. You almost feel as if you could converse with the departed. I do not know of anything so touchingly powerful in vividly bringing back the treasured incidents and memories of one's life as the sight of such humble objects. Every one has, no doubt, a treasured store of such material records of a well-remembered portion of his past life. These strike, as it were, the keynote to thoughts that bring back in vivid form the most cherished remembrances of our lives. On many occasions I have seen at sale rooms long treasured hoards of such objects thrown together in a heap as mere rubbish. And yet these had been to some the sources of many pleasant thoughts and recollections, But the last final break-up has come, and the personal belongings of some departed kind heart are scattered far and wide. These touching relics of a long life, which had almost become part of himself, are "knocked down" to the lowest class of bidders. It is a sad sight to witness the uncared for dispersion of such objects—objects that had been lovingly stored up as the most valued of personal treasures. I could have wished that, as was the practice in remote antiquity, such touching relics were buried with the dead, as their most fitting repository. Then they might have left some record, instead of being desecrated by the harpies who wait at sales for such "job lots."
Behold us, then, settled down at Hammerfield for life. We had plenty to do. My workshop was fully equipped. My hobbies were there, and I could work them to my heart's content. The walls of our various rooms were soon hung with pictures, and other works of art, suggestive of many pleasant associations of former days. Our library book-case was crowded with old friends, in the shape of books that had been read and re-read many times, until they had become almost part of ourselves. Old Lancashire friends made their way to us when "up in town," and expressed themselves delighted with our pleasant house and its beautiful surroundings.
The continuous planting of the shrubs and trees gave us great pleasure. Those already planted had grown luxuriantly, fed by the fertile soil and the pure air. Indeed, in course of time they required the judicious use of the axe in order to allow the fittest to survive and grow at their own free will. Trees contrive to manage their own affairs without the necessity of much labour or interference. The "survival of the fittest" prevails here as elsewhere. It is always a pleasure to watch them. There are many ordinary old-fashioned roadside flowering plants which I esteem for their vigorous beauty, and I enjoy seeing them assume the careless grace of Nature.
The greenhouse is also a source of pleasure, especially to my dear wife. It is full of flowers of all kinds, of which she is devotedly fond. They supply her with subjects for her brush or her needle. She both paints them and works them by her needle in beautiful forms and groups. This is one of her many favourite hobbies. All this is suitable to our fireside employments, and makes the days and the evenings pass pleasantly away.
CHAPTER 21. Active leisure.
When James Watt retired from business towards the close of his useful and admirable life, he spoke to his friends of occupying himself with "ingenious trifles," and of turning "some of his idle thoughts" upon the invention of an arithmetical machine and a machine for copying sculpture. These and other useful works occupied his attention for many years.
It was the same with myself. I had good health (which Watt had not) and abundant energy. When I retired from business I was only forty-eight years old, which may be considered the prime of life. But I had plenty of hobbies, perhaps the chief of which was Astronomy. No sooner had I settled at Hammerfield than I had my telescopes brought out and mounted. The fine clear skies with which we were favoured, furnished me with abundant opportunities for the use of my instruments. I began again my investigations on the Sun and the Moon, and made some original discoveries, of which more anon.
Early in the year 1858 I received a pressing invitation from the Council of the Edinburgh Philosophical Society to give a lecture before their members on the Structure of the Lunar Surface. As the subject was a favourite one with me, and as I had continued my investigations and increased my store of drawings since I had last appeared before an Edinburgh audience, I cheerfully complied with their request. I accordingly gave my lecture before a crowded meeting in the Queen Street Lecture Hall.
The audience appeared to be so earnestly interested by the subject that I offered to appear before them on two successive evenings and give any viva voce explanations about the drawings which those present might desire. This deviation from the formality of a regular lecture was attended with the happiest results. Edinburgh always supplies a highly-intelligent audience, and the cleverest and brightest were ready with their questions. I was thus enabled to elucidate the lecture and to expand many of the most interesting points connected with the moon's surface, such as might formerly have appeared obscure. These questioning lectures gave the highest satisfaction. They satisfied myself as well as the audience, who went away filled with the most graphic information I could give them on the subject.
But not the least interesting part of my visit to Edinburgh on this occasion was the renewed intercourse which I enjoyed with many of my old friends. Among these were my venerable friend Professor Pillans, Charles Maclaren (editor of the Scotsman), and Robert Chambers. We had a long dander together through the Old Town, our talk being in broad Scotch. Pillans was one of the fine old Edinburgh Liberals, who stuck to his principles through good report and through evil. In his position as Rector of the High School, he had given rare evidence of his excellence as a classical scholar. He was afterwards promoted to be a Professor in the University. He had as his pupils some of the most excellent men of my time. Amongst his intimate friends were Sydney Smith, Brougham, Jeffrey, Cockburn—men who gave so special a character to the Edinburgh society of that time.
We had a delightful stroll through some of the most remarkable parts of the Old Town, with Robert Chambers as our guide. We next mounted Arthur's Seat to observe some of the manifestations of volcanic action, which had given such a remarkable structure to the mountain. On this subject, Charles Maclaren was one of the best living expounders. He was an admirable geologist, and had closely observed the features of volcanic action round his native city. Robert Chambers then took us to see the glacial grooved rocks on another part of the mountain. On this subject he was a master. It was a vast treat to me to see those distinct evidences of actions so remotely separated in point of geological time—in respect to which even a million of years is a humble approximate unit* [footnote… "It is to our ever-dropping climate, with its hundred and fifty-two days of annual rain, that we owe our vegetable mould with its rich and beauteous mantle of sward and foliage. And next, stripping from off the landscape its sands and gravels, we see its underlying boulder-clays, dingy and gray, and here presenting their vast ice-borne stones, and there its iceberg pavements. And these clays in turn stripped away, the bare rocks appear, various in colour and uneven in surface, but everywhere grooved and polished, from the sea level and beneath it, to the height of more than a thousand feet, by evidently the same agent that careered along the pavements and transported the great stones.
HUGH MILLER'S Geological Features of Edinburgh and its Neighbourhood. …]
What a fine subject for a picture the group would have made! with the great volcanic summit of the mountain behind, the noble romantic city in the near distance, and the animated intelligent countenaces of the demonstrators, with the venerable Pillans eagerly listening—for the Professor was then in his eighty-eighth year. I had the happiness of receiving a visit from him at Hammerfield in the following year. He was still hale and active; and although I was comparatively a boy to him, he was as bright and clear-headed as he had been forty years before.
In the course of the same year I accompanied my wife and my sister Charlotte on a visit to the Continent. It was their first sojourn in foreign parts. I was able, in some respects, to act as their guide. Our visit to Paris was most agreeable. During the three weeks we were there, we visited the Louvre, the Luxembourg, Versailles, and the parts round about. We made many visits to the Hotel Cluny, and inspected its most interesting contents, as well as the Roman baths and that part of the building devoted to Roman antiquities. We were especially delighted with the apartments of the Archbishop of Paris, now hung with fine old tapestry and provided with authentic specimens of mediaeval furniture. The quaint old cabinets were beautiful studies; and many artists were at work painting them in oil. Everything was in harmony. When the sun shone in through the windows in long beams of coloured light, illuminating portions of the antique furniture, the pictures were perfect. We were much interested also by the chapel in which Mary Queen of Scots was married to the Dauphin. It is still in complete preservation. The Gothic details of the chapel are quite a study; and the whole of these and the contents of this interesting Museum form a school of art of the best kind.
From Paris we paid a visit to Chartres, which contains one of the most magnificent cathedrals in France. Its dimensions are vast, its proportions are elegant, and its painted glass is unequalled. Nothing can be more beautiful than its three rose-windows. But I am not writing a guide-book, and I must forbear. After a few days more at Paris we proceeded south, and visited Lyons, Avignon, and Nismes, on our way to Marseilles. I have already described Nismes in my previous visit to France. I revisited the Roman amphitheatre, the Maison Quarree, that perfect Roman temple, which, standing as it does in an open square, is seen to full advantage. We also went to see the magnificent Roman aqueduct at Pont du Gard. The sight of the noble structure well repays a visit. It consists of three tiers of arches. Its magnitude, the skilful fitting of its enormous blocks, makes a powerful impression on the mind. It has stood there, in that solitary wooded valley, for upwards of sixteen centuries; and it is still as well fitted for conveying its aqueduct of water as ever. I have seen nothing to compare with it, even at Rome. It throws all our architectural buildings into the shade. On our way back from Marseilles to Paris we visited Grenoble and its surrounding beautiful Alpine scenery. Then to Chambery, and afterwards to Chamounix, where we obtained a splendid view of Mont Blanc. We returned home by way of Geneva and Paris, vastly delighted with our most enjoyable journey.
I return to another of my hobbies. I had an earnest desire to acquire the art and mystery of practical photography. I bought the necessary apparatus, together with the chemicals; and before long I became an expert in the use of the positive and negative collodion process, including the printing from negatives, in all the details of that wonderful and delightful art. To any one who has some artistic taste, photography, both in its interesting processes and glorious results, becomes a most attractive and almost engrossing pursuit. It is a delightful means of educating the eye for artistic feeling, as well as of educating the hands in delicate manipulation. I know of nothing equal to photography as a means of advancing one's knowledge in these respects. I had long meditated a work "On the Moon," and it was for this purpose more especially that I was earnest in endeavouring to acquire the necessary practical skill. I was soon enabled to obtain photographic copies of the elaborate models of parts of the moon's, surface, which I had long before prepared. These copies were hailed by the highest authorities in this special department of astronomical research as the best examples of the moon's surface which had yet been produced.
In reference to this subject, as well as to my researches into the structure of the sun's surface, I had the inestimable happiness of securing the friendship of that noble philosopher, Sir John Herschel. His visits to me, and my visits to him, have left in my memory the most cherished and happy recollections. Of all the scientific men I have had the happiness of meeting, Sir John stands supremely at the head of the list. He combined profound knowledge with perfect humility. He was simple, earnest, and companionable, He was entirely free from assumptions of superiority, and, still learning, would listen attentively to the humblest student. He was ready to counsel and instruct, as well as to receive information. He would sit down in my workshop, and see me go through the various technical processes of casting, grinding, and polishing specula for reflecting telescopes. That was a pleasure to him, and a vast treat to me.
I had been busily occupied for some time in making careful investigations into the dark spots upon the Sun's surface. These spots are of extraordinary dimensions, sometimes more than 10,000 miles in diameter. Our world might be dropped into them. I observed that the spots were sometimes bridged over by a streak of light, formed of willow-leaf-shaped objects. They were apparently possessed of voluntary motion, and moved from one side of the spot to the other. These flakes were evidently the immediate sources of the solar light and heat. I wrote a paper on the subject, which I sent to the Literary and Philosophical Society of Manchester.* [footnote… Memoirs of the Literary and Philosophical Society of Manchester, 3d series, vol. i. p. 407. My first discovery of the "Willow-leaf" objects on the Sun's surface was made in June 1860.I afterwards obtained several glimpses of them from time to time.But the occasions are very rare when the bright sun can be seen in a tranquil atmosphere free from vibrations, and when the delicate objects on its surface can be clearly defined. It was not until the 5th of June 1864 that I obtained the finest sight of the Sun's spots and the Willow-leaf objects; it was then that I made a careful drawing of them, from which the annexed faithful engraving has been produced. Indeed I never had a better sight of this extraordinary aspect of the Sun than on that day. …]
The results of my observations were of so novel a character that astronomers for some time hesitated to accept them as facts. Yet Sir John Herschel, the chief of astronomers, declared them to be "a most wonderful discovery"
[Image] Group of sun spots as seen by James Nasmyth, 5th June 1864.
I received a letter from Sir John, dated Collingwood, 2lst of May 1861, in which he said:
"I am very much obliged to you for your note, and by the sight of your drawings, which Mr. Maclaren was so kind as to bring over here the other day. I suppose there can be no doubt as to the reality of the willow-leaved flakes, and in that case they certainly are the most marvellous phenomena that have yet turned up—had almost said in all Nature—certainly in all Astronomy.
"What can they be? Are they huge phosphorised fishes? If so, what monsters! Or are they crystals? a kind of igneous snow-flakes? floating in a fluid of their own, or very nearly their own, specific gravity? Some kind of solidity or coherence they must have, or they would not retain their shape in the violent movements of the atmosphere which the change of the spots indicate.
"I observe that in the bridges all their axes have an approximate parallelism, and that in the penumbra they are dispersed, radiating from the inside and the outside of the spot, giving rise to that striated appearance which is familiar to all observers of the spots.
"I am very glad that you have pitched your tent in this part of the world, and I only wish it were a little nearer. You will anyhow have the advantage at Penshurst of a much clearer atmosphere than in the north; but here, nearer the coast, I think we are still better off. "Mr. Maclaren holds out the prospect of our meeting you at Pachley at no distant period, and I hope you will find your way ere long to Collingwood. I have no instruments or astronomical apparatus to show you, but a remarkably pretty country, which is beginning to put on (rather late) its gala dress of spring?'
Sir John afterwards requested my permission to insert in his Outlines of Astronomy, of which a new edition was about to appear, a representation of "the willow-leaved structure of the Sun's surface," —which had been published in the Manchester transactions,—to which I gladly gave my assent. Sir John thus expresses himself on the subject: —"The curious appearance of the 'pores' of the Sun's surface has lately received a most singular and unexpected interpretation from the remarkable discovery of Mr. J. Nasmyth, who, from a series of observations made with a reflecting telescope of his own construction under very high magnifying powers, and under exceptional circumstances of tranquillity and definition, has come to the conclusion that these pores are the polygonal interstices between certain luminous objects of an exceedingly definite shape and general uniformity of size, whose form (at least as seen in projection in the central portions of the disc) is that of the oblong leaves of a willow tree. These cover the whole disc of the Sun (except in the space occupied by spots) in countless millions, and lie crossing each other in every imaginable direction…. This most astonishing revelation has been confirmed to a certain considerable extent, and with some modifications as to the form of the objects, their exact uniformity of size and resemblance of figure, by Messrs. De la Rue, Pritchard and Stone in England, and M. Secchi in Rome."
On the 25th of February 1864, I received a communication from
Mr. E. J. Stone, first assistant at the Royal Observatory, Greenwich.
The Astronomer-Royal, he said, "has placed in my hands your letter of February 20. Your discovery of the 'willow leaves' on the Solar photosphere having been brought forward at one of the late meetings of the Royal Astronomical Society, my attention was attracted to the subject. At my request, the Astronomer-Royal ordered of Mr. J. Simms a reflecting eye-piece for our great equatorial. The eye-piece was completed about the end of January last, and at the first good opportunity I turned the telescope on the Sun.
"I may state that my impression was, and it appears to have been the impression of several of the assistants here, that the willow leaves stand out dark against the luminous photosphere. On looking at the Sun, I was at once struck with the apparent resolvability of its mottled appearance. The whole disc of the Sun, so far as I examined it, appeared to be covered over with relatively bright rice-like particles, and the mottled appearance seemed to be produced by the interlacing of these particles.
"I could not observe any particular arrangement of the particles, but they appeared to be more numerous in some parts than in others. I have used the word 'rice-like' merely to convey a rough impression of their form. I have seen them on two occasions since, but not so well as on the first day, when the definition was exceedingly good.
"on the first day that I saw them I called Mr Dunkin's attention to them. He appears to have seen them. He says, however, that he should not have noticed them if his attention had not been called to them."
The Astronomer Royal, in his report to the Admiralty on my discovery, said:
"an examination of the Sun's surface with the South-East Equatorial, under favourable circumstances, has convinced me of the accuracy of the description, which compares it with interlacing willow leaves or rice grains."
In March 1864 I received a letter from my friend De la Rue, dated from his observatory at Cranford, Middlesex, in which he said: "I like good honest doubting. Before I had seen with my own eyes your willow leaves, I doubted their real existence, but I did not doubt your having seen what you had drawn. But when I actually saw them for the first time, I could not restrain the exclamation, ' Why, here are Nasmyth's willow leaves! ' It requires a very fine state of the atmosphere to permit of their being seen, as I have seen them on three or four occasions, when their substantial reality can no longer be doubted."* [footnote… Let me give another letter from my friend, dated the Observatory, Cranford, Middlesex, October 26, 1864. He said:- "I am quite pleased to learn that you like the large photograph. The first given to my friend was destined for and sent to you. No one has so great a claim on the fruit of my labours; for you inoculated me with the love of star-gazing, and gave me invaluable aid and advice in figuring specula. I daresay you may remember the first occasion on which I saw a reflecting telescope, which was then being tried on the sun in a pattern loft at Patricroft. You may also recall the volumes you wrote in answer to my troublesome questions. Yours very sincerely WARREN DE LA RUE." …]
Sir John Herschel confirmed this information in a letter which I received from him in the following May. He said "that Mr. De la Rue and a foreign gentleman, Hugo Muller, had been very successful in seeing and delineating the 'willow leaves' They are represented by Mr. M. as packed together on the edge of a spot, and appear rather like a bunch of bristles or thorns. In other respects the individual forms agree very well with your delineations." Another observer had discovered a marvellous resemblance between the solar spots and the hollows left by the breaking and subsidence of bubbles, which rise when oil varnish, which has moisture in it, is boiled, and the streaky channels are left by the retiring liquid. "I cannot help," adds Sir John, "fancying a bare possibility of some upward outbreak, followed by a retreat of some gaseous matter, or some dilated portion of the general atmosphere struggling upwards, and at the same time expanding outwards. I can conceive of an up-surge of some highly compressed matter, which relieved of pressure, will dilate laterally and upwards to an enormous extent (as Poullett Scrope supposes of his lavas full of compressed gases and steam), producing the spots, and, in that case, the furrows might equally well arise in the origination as in the closing in of a spot."
I had the honour and happiness of receiving a visit from Sir John Herschel at my house at Hammerfield in the summer of 1864. He was accompanied by his daughter. They spent several days with us. The weather was most enjoyable. I had much conversation with Sir John as to the Sun spots and willow-leaf-shaped objects on the Sun's surface, as well as about my drawings of the Moon. I exhibited to him my apparatus for obtaining sound castings of specula for reflecting telescopes. I compounded the alloy, melted it, and cast a 10-inch speculum on my peculiar common-sense system. I introduced the molten alloy, chilled it in a metal mould, by which every chance of flaws and imperfections is obviated. I also showed him the action and results of my machine, by which I obtained the most exquisite polish and figure for the speculum. Sir John was in the highest degree cognisant of the importance of these details, as contributing to the final excellent result. It was therefore with great pleasure that I could exhibit these practical details before so competent a judge.
We had a great set-to one day in blowing iridescent soap bubbles from a mixture of soap and glycerine. Some of the bubbles were of about fifteen inches diameter. By carefully covering them with a bell glass, we kept them for about thirty-six hours, while they went through their changes of brilliant colour, ending in deep blue. I contrived this method of preserving them by placing a dish of water below, within the covering bell glass, by means of which the dampness of the air prevented evaporation of the bubble. This dodge of mine vastly delighted Sir John, as it allowed him to watch the exquisite series of iridescent tints at his tranquil leisure.
[Image] From a photograph of the Moon, exhibiting the bright radial
lines.
[Image] Glass globe cracked by internal pressure, in illustration of
the cause of the bright radial lines seen on the moon.
I had also the pleasure of showing him my experiment of cracking a glass globe filled with water and hermetically sealed. The water was then slightly expanded, on which the glass cracked. This was my method of explaining the nature of the action which, at some previous period of the cosmical history of the Moon, had produced those bright radiating lines that diverge from the lunar volcanic craters. Sir John expressed his delight at witnessing my practical illustration of this hitherto unexplained subject, and he considered it quite conclusive. I also produced my enlarged drawings of the Moon's surface, which I had made at the side of my telescope. These greatly pleased him and he earnestly urged me to publish them, accompanied with a descriptive account of the conclusions I had arrived at. I then determined to proceed with the preparations which I had already made for my long contemplated work.
Among the many things that I showed Sir John while at Hammerfield, was a piece of white calico on which I had got printed one million spots. [footnote… At a recent meeting of the Metropolitan Railway Company I exhibited one million of letters, in order to show the number of passengers (thirty-seven millions) that had been conveyed during the previous twelve months. This number was so vast that my method only helped the meeting to understand what had been done in the way of conveyance. Mr. Macdonald of the Times, supplied me with one million type impressions, contained in sixty average columns of the Times newspaper. …]
This was for the purpose of exhibiting one million in visible form. In astronomical subjects a million is a sort of unit, and it occurred to me to show what a million really is. Sir John was delighted and astonished at the sight. He went carefully over the outstretched piece with his rule, measured its length and breath, and verified its correctness.
I also exhibited to him a diagram, which I had distributed amongst the geologists at the meeting of the British Association at Ipswich in 1851, showing a portion of the earth's curve, to the scale of one-tenth of an inch to a mile. I set out the height of Mont Blanc, Etna, and also the depth of the deepest mine, as showing the almost incredible minimum of knowledge we possess about even the merest surface of the globe. This diagram was hailed by many as of much value, as conveying a correct idea of the relative magnitude of geological phenomena in comparison with that of the earth itself:
On this subject Sir Thomas Mitchell, Surveyor-General of Australia, wrote to me at the time: "I will not obtrude upon you my crude notions of my own, but merely say that you could not have sent the 'Geological Standard Scale' to one who better deserved it, if the claim in such favour is, as I suppose, to be estimated by the amount of the time of one whole life, applied to the survey of great mountain ranges, and coasts, rivers, etc. By this long practice of mine, you may know how appreciable this satisfactory standard scale is to your humble servant.
In the winter of 1865 I visited Italy. While at Rome, in April, I had the pleasure of meeting Otto W. von Struve, the celebrated Russian astronomer. He invited me to accompany him on a visit to Father Secchi at his fine observatory of the Collegio Romano. I accepted the invitation with pleasure. We duly reached the Observatory when Struve introduced me to the Father. Secchi gave me a most cordial and unlooked-for welcome. "This," he said, "is a most extraordinary interview; as I am at this moment making a representation of your willow-leaf-shaped constituents of the Solar surface!" He then pointed to a large black board, which he had daubed over with glue and was sprinkling over ( when we came in) with rice grains "That," said he, "is what I feel to be a most excellent representation of your discovery as I see it, verified by the aid of my telescope." It appeared to Father Secchi so singular a circumstance that I should come upon him in this sudden manner, while he was for the first time engaged in representing what I had (on the spur of the moment when first seeing them) described as willow-leaf-shaped objects. I thought that his representation of them, by scattering rice grains over his glue-covered black board, was apt and admirable; and so did Otto Struve. This chance meeting with these two admirable astronomers was one of the little bits of romance in my life.
I returned to England shortly after. Among our visitors at Hammerfield was Lord Lyndhurst. He was in his ninetieth year when he paid a visit to Tunbridge Wells. Charles Greville, Secretary to the Privy Council, wrote to me, saying that his Lordship complained much of the want of society, and asked me to call upon him. I did so, and found him cheerful and happy.
I afterwards sent him a present of some of my drawings. He answered: "A thousand thanks for the charming etchings. I am especially interested in Robinson Crusoe. He looks very comfortable, but I can't see his bed, which troubles me. The election ('Everybody for ever!') is wonderful. I should not like to be there. I hope we shall go to you again one of these days, and have another peep into that wonderful telescope."
To return to Sir John Herschel, We returned his visit at his house at Collingwood, near Hawkhurst. I found him in the garden, down upon his knees, collecting crocus bulbs for next year's planting. Like myself, he loved gardening, and was never tired of it. I mention this as an instance of his simple zeal in entering practically into all that interested him. At home he was the happy father and lover of his family. One of his favourite pastimes, when surrounded by his children in the evening, was telling them stories. He was most happy and entertaining in this tranquil occupation. His masterly intellect could grasp the world and all its visible contents, and yet descend to entertain his children with extemporised tales. He possessed information of the most varied kind, which he communicated with perfect simplicity and artlessness! His profound astronomical knowledge was combined with a rich store of mechanical and manipulative faculty, which enabled him to take a keen interest in all the technical arts which so materially aid in the progress of science. I shall never forget the happy days that he spent with me in my workshop. His visits have left in my mind the most cherished recollections. Our friendly intercourse continued unbroken to the day of his death. The following is the last letter I received from him:
COLLINGWOOD, March 10, 1871. "MY DEAR SIR—A great many thanks for the opportunity of seeing your most exquisite photographs from models of lunar mountains. I hope you will publish them. They will create quite an electric sensation. Would not one or two specimens of the apparently nonvolcanic mountain ranges, bordering on the great plains, add to the interest? Excuse my writing more, as I pen this lying on my back in bed, to which a fierce attack of bronchitis condemns me. With best regards to Mrs. Nasmyth, believe me yours very truly,
" J. F. W. HERSCHEL."
Scientific knowledge seems to travel slowly, It was not until the year 1875, more than fourteen years after my discovery of the willow-leaved bridges over the Sun's spots that I understood they had been accepted in America. I learned this from my dear friend William Lassell. His letter was as follows: —"I see the Americans are appreciating your solar observations. A communication I have lately received from the Alleghany Observatory remarks 'that he (Mr. Nasmyth) appears to have been the first to distinctly call attention to the singular individuality of the minute components of the photosphere; and this seems in fairness to entitle him to the credit of an important discovery, with which his name should remain associated.'"
I proceeded to do that which Sir John Herschel had so earnestly recommended, that is, to write out my observations on the Moon. It was a very serious matter, for I had never written a book before. It occupied me many years, though I had the kind assistance of my friend James Carpenter, then of the Royal Observatory, Greenwich. The volcanoes and craters, and general landscape scenery of the Moon, had to be photographed and engraved, and this caused great labour.
At length the book, entitled The Moon, considered as a Planet, a World, and a Satellite, appeared in November 1874. It was received with much favour and passed into a second edition. A courteous and kind review of the book appeared in the Edinburgh; and the notices in other periodicals were equally favourable. I dedicated the volume to the Duke of Argyll, because I had been so long associated with him in geological affairs, and also because of the deep friendship which I entertained for his Grace. I presented the volume to him as well as to many other of my astronomical friends. I might quote their answers at great length, from the Astronomer-Royal downwards. But I will quote two—one from a Royal Academician and another from a Cardinal. The first was from Philip H. Calderon. He said:
"Let me thank you many times for your kind letter, and for your glorious book. It arrived at twelve to-day, and there has been no painting since. Once having taken it up, attracted by the illustrations, I could not put it down again. I forgot everything; and, indeed, I have been up in the Moon. As soon as these few words of thanks are given, I am going up into the Moon again. What a comfort it is to read a scientific work which is quite clear, and what a gift it is to write thus!
"The photographs took my breath away. I could not understand how you did them, and your explanation of how you built the models from your drawings only changed the wonder into admiration. Only an artist could have said what you say about the education of the eye and of the hand. You may well understand how it went home to me. Ever gratefully yours,
PHILIP H. CALDERON."
I now proceed to the Cardinal. I was present at one of the receptions of the President of the Royal Society at Burlington House, when I was introduced to Cardinal Manning as "The Steam Hammer!" After a cordial reception he suddenly said, "But are you not also the Man in the Moon?" Yes, your Eminence. I have written a book about the Moon, and I shall be glad if you will accept a copy of it?" "By all means," he said, "and I thank you for the offer very much." I accordingly sent the copy, and received the following answer:
"MY DEAR MR.NASMYTH—When I asked you to send me your book on the Moon, I had no idea of its bulk and value, and I feel ashamed of my importunity, yet more than half delighted at my sturdy begging.
"I thank you for it very sincerely. My life is one of endless work, leaving me few moments for reading. But such books as yours refresh me like a clover field.
"I hope I may have an opportunity of renewing our conversation.
Believe me always truly yours, HENRY, CARDINAL MANNING."
I may also mention that I received a charming letter from Miss Herschel, the daughter of the late Astronomer.
"Is it possible," she said, "that this beautiful book is destined by you as a gift to my most unworthy self? I do not know, indeed, how sufficiently to thank you, or even to express my delight in being possessed of so exquisite and valuable a work, made so valuable, too, by the most kind inscription on the first page! I fear I shall be very very far from understanding the theories developed in the book, though we have been endeavouring to gather some faint notion of them from the reviews we have seen; but it will be of the greatest interest for us to try and follow them under your guidance, and with the help of these perfectly enchanting photographs, which, I think, one could never be tired of looking at.
"How well I remember the original photographs, and the oil painting which you sent for dear papa's inspection, and which he did so enjoy! and also the experiment with the glass globe, in which he was so interested, at your own house. We cannot but think how he would have appreciated your researches, and what pleasure this lovely book would have given him. Indeed, I shall treasure it especially as a remembrance of that visit, which is so completely connected in my thoughts with him, as well as with your cordial kindness, as a precious souvenir, of which let me once more offer you my heartfelt thanks. I remain, my dear sir, yours very truly and gratefully,
"ISABELLA HERSCHEL."
I cannot refrain from adding the communication I received from my dear old friend William Lassell. "I do not know," he said, "how sufficiently to thank you for your most kind letter, and the superb present which almost immediately followed it. My pleasure was greatly enhanced by the consideration of how far this splendid work must add to your fame and gratify the scientific world. The illustrations are magnificent, and I am persuaded that no book has ever been published before which gives so faithful, accurate, and comprehensive a picture of the surface of the Moon. The work must have cost you much time, thought, and labour, and I doubt not you will now receive a gratifying, if not an adequate reward."
After reading the book Mr. Lassell again wrote to me. "I am indebted to your beautiful book, "he said, "for a deeper interest in the Moon than I ever felt before…. I see many of your pictures have been taken when the Moon was waning, which tells me of many a shivering exposure you must have had in the early mornings,… I was sorry to find from your letter that you had a severe cold, which made you very unwell. I hope you have ere this perfectly recovered. I suppose maladies of this kind must be expected to take rather severe hold of us now, as we are both past the meridian of life. I am, however, very thankful for the measure of health I enjoy, and the pleasure mechanical pursuits give me. I fully sympathise with you in the contempt (shall I say?) which you feel for the taste of so many people who find their chief pleasure in 'killing something,' and how often their pleasures are fatal! Two distinguished men killed only the other day in hunting. For my part I would rather take to the bicycle and do my seventeen miles within the hour."
He proceeds: "I have no doubt your windmill is very nicely contrived, and has afforded you much pleasure in constructing it. The only drawback to it is, that in this variable climate it is apt to strike work, and in the midst of a job of polishing I fear no increase of wages would induce it to complete its task! If water were plentiful, you might make it pump up a quantity when the wind served, to be used as a motive power when you chose."
This reference alludes to a windmill which I erected on the top of my workshop, to drive the apparatus below. It was the mirror of a reflecting telescope which was in progress. The windmill went on night and day, and polished the speculum while I slept. In the small hours of the morning I keeked through the corner of the window blinds and saw it hard at work. I prefer, however, a small steam-engine, which works much more regularly.
It is time to come to an end of my Recollections. I have endeavoured to give a brief resume of my life and labours. I hope they may prove interesting as well as useful to others. Thanks to a good constitution and a frame invigorated by work, I continue to lead, with my dear wife, a happy life. I still take a deep interest in mechanics, in astronomy, and in art. It is a pleasure to me to run up to London and enjoy the collections at the National Gallery, South Kensington, and the Royal Academy. The Crystal Palace continues to attract a share of my attention, though, since the fire, it has been greatly altered. I miss, too, many of the dear accustomed faces of the old friends we used to meet there. Still we visit it, and leave to memory the filling up of what is gone. All things change, and we with them. The following Dial of Life gives a brief summary of my career. It shows the brevity of life, and indicates the tale that is soon told. The first part of the semicircle includes the passage from infancy to boyhood and manhood. While that period lasts, time seems to pass very slowly. We long to be men, and doing men's work. What I have called The Tableland of Life is then reached. Ordinary observation shows that between thirty and fifty the full strength of body and mind is reached; and at that period we energise our faculties to the utmost.
[Image] The Dial of Life
Those who are blessed with good health and a sound constitution may prolong the period of energy to sixty or even seventy; but Nature's laws must be obeyed, and the period of decline begins, and goes on with accelerated rapidity. Then comes Old Age; and as we descend the semicircle towards eighty, we find that the remnant of life becomes vague and cloudy. By shading off, as I have done, the portion of the area of the diagram according to the individual age, every one may see how much of life is consumed, and what is left—D.V.. Here is my brief record:
AGE YEAR. — 1808. BORN 19TH AUGUST. 9 1817. WENT TO THE HIGH SCHOOL, EDINBURGH. 13 1821. ATTENDED THE SCHOOL OF ARTS. 21 1829. WENT TO LONDON, TO MAUDSLAY'S. 23 1831. RETURNED TO EDINBURGH, TO MAKE MY ENGINEERS' TOOLS. 26 1834. WENT TO MANCHESTER, TO BEGIN BUSINESS. 28 1836. REMOVED TO PATRICROFT, AND BUILT THE BRIDGEWATER FOUNDRY. 31 1839. INVENTED THE STEAM HAMMER. 32 1840. MARRIAGE. 34 1842. FIRST VISIT TO FRANCE AND ITALY. 35 1843. VISIT TO ST. PETERSBURG, STOCKHOLM, DANNEMORA. 37 1845. APPLICATION OF THE STEAM HAMMER TO PILE-DRIVING. 48 1856. RETIRED FROM BUSINESS, TO ENJOY THE REST OF MY LIFE IN THE ACTIVE PURSUIT OF MY MOST FAVOURITE OCCUPATIONS.
I have not in this list referred to my investigations in connection with astronomy. All this will be found referred to in the text. It only remains for me to say that I append a resume of my inventions, contrivances, and workshop "dodges," to give the reader a summary idea of the Active Life of a working mechanic. And with this I end my tale.
CHRONOLOGICAL LIST OF MECHANICAL INVENTIONS AND TECHNICAL CONTRIVANCES.
by James Nasmyth.
1825. A mode of applying Steam Power for the Traction of Canal Barges, without injury to the Canal Banks.
A CANAL having been formed to connect Edinburgh with the Forth and Clyde Canal, and so to give a direct waterway communication between Edinburgh and Glasgow, I heard much talk about the desirableness of substituting Steam for Horse power as the means of moving the boats and barges along the canal. But, as the action of paddle wheels had been found destructive to the canal banks, no scheme of that nature could be entertained. Although a tyro in such matters, I made an attempt to solve the problem, and accordingly prepared drawings, with a description of my design, for employing Steam power as the tractive agency for trains of canal barges, in such a manner as to obviate all risk of injury to the banks.
[Image]
The scheme consisted in laying a chain along the bottom of the canal, and of passing any part of its length between three grooved and notched pulleys or rollers, made to revolve with suitable velocity by means of a small steam-engine placed in a tug-boat, to the stern of which a train of barges was attached.* [footnote… Had this simple means of "tugging" vessels through water-ways been employed in our late attempts to ascend the rapids of the Nile, some very important results might have issued from its adoption. …] The steam-engine could thus warp its way along the chain, taking it up between the rollers of the bow of the tug-boat, and dropping it into the water at the stern, so as to leave the chain at the service of the next following tug-boat with its attached train of barges. By this simple mode of employing the power of a steam-engine for canal boat traction, all risk of injury to the banks would be avoided, as the chain and not the water of the canal was the fulcrum or resistance which the steam-engine on the tug-boat operated upon in thus warping its way along the chain; and thus effectually, without slip or other waste of power, dragging along the train of barges attached to the stern of the steam-tug. I had arranged for two separate chains, so as to allow trains of barges to be conveyed along the canal in opposite directions, without interfering with each other.
I submitted a complete set of drawings, and a full description of my design in all its details, to the directors of the Canal Company; and I received a complimentary acknowledgment of them in writing. But such was the prejudice that existed, in consequence of the injury to the canal banks resulting from the use of paddle Wheels, that it extended to the use of steam power in any form, as a substitute for ordinary horse traction; and although I had taken every care to point out the essential difference of my system (as above indicated) by which all such objections were obviated, my design was at length courteously declined, and the old system of horse traction continued.
In 1845 I had the pleasure to see this simple mode of moving vessels along a definite course in most successful action at the ferry across the Hamoaze at Devonport, in which my system of employing the power of a steam-engine on board the ferry boat, to warp its way along a submerged chain lying along the bottom of the channel from side to side of the ferry, was most ably carried out by my late excellent friend, James Rendell, Esq., C.E., and is still, I believe, in daily action, giving every satisfaction.
1826. An Instrument for Measuring the Total and Comparative Expansion of all Solid Bodies.
My kind friend and patron, Professor Leslie, being engaged in some investigations in which it was essential to know the exact comparative total expansion in bulk of metals and other solid bodies, under the same number of degrees of heat, mentioned the subject in the course of conversation. The instrument at that time in use was defective in principle as well as in construction, and the results of its application were untrustworthy. As the Professor had done me the honour to request me to assist him in his experiments, I had the happiness to suggest an arrangement of apparatus which I thought might obviate the sources of error; and, with his approval, I proceeded to put it in operation.
My contrivance consisted of an arrangement by means of which the metal bar or other solid substance, whose total expansion under a given number of degrees of heat had to be measured, was in a manner itself converted into a thermometer. Absolutely equal bulks of each solid were placed inside a metal tube or vessel, and surrounded with an exact equal quantity of water at one and the same normal temperature. A cap or cover, having a suitable length of thermometer tube attached to it, was then screwed down, and the water of the index tube was adjusted to the zero point of the scale attached to it, the whole being at say 50deg of heat, as the normal temperature in each case. The apparatus was then heated up to say 200deg by immersion in water at that temperature. The expansion of the enclosed bar of metal or other solid substance under experiment caused the water to rise above the zero, and it was accordingly so indicated on the scale attached to the cap tube. In this way we had a thermometer whose bulb was for the time being filled with the solid under investigation,—the water surrounding it imply acting as the means by which the expansion of each solid under trial was rendered visible, and its amount capable of being ascertained and recorded with the utmost exactness, as the expansion of the water was in every case the same, and also that of the instrument itself which was "a constant quantity."
In this way we obtained the correct relative amount of expansion in bulk of all the solid substances experimented upon. That each bar of metal or other solid substance was of absolutely equal bulk, was readily ascertained by finding that each, when weighed in water, lost the exact same weight.
[Image] James Nasmyth's Expansometer, 1826.
My friend, Sir David Brewster, was so much pleased with the instrument that he published a drawing and description of it in the Edinburgh Philosophical Journal, of which he was then editor.
1827. A Method of increasing the Effectiveness of Steam by super-heating it on its Passage from the Boiler to the Engine.
One or the earliest mechanical contrivances which I made was for preventing water, in a liquid form, from passing along with the steam from the boiler to the cylinder of the steam-engine. The first steam-engine I made was employed in grinding oil colours for my father's use in his paintings. When I set this engine to work for the first time I was annoyed by slight jerks which now and then disturbed the otherwise smooth and regular action of the machine. After careful examination I found that these jerks were caused by the small quantities of water that were occasionally carried along with the current of the steam, and deposited in the cylinder, where it accumulated above and below the piston, and thus produced the jerks.
In order to remove the cause of these irregularities, I placed a considerable portion of the length of the pipe which conveyed the steam from the boiler to the engine within the highly heated side flue of the boiler, so that any portion of water in the liquid form which might chance to pass along with the steam, might, ere it reached the cylinder, traverse this highly-heated steam pipe, and, in doing so, be converted into perfectly dry steam, and in that condition enter the cylinder. On carrying this simple arrangement into practice, I found the result to be in every way satisfactory. The active little steam-engine thence-forward performed its work in the most smooth and regular manner.
So far as I am aware, this early effort of mine at mechanical contrivance was the first introduction of what has since been termed "super-heated steam"—a system now extensively employed, and yielding important results, especially in the case of marine steam-engines. Without such means of supplying dry steam to the engines, the latter are specially liable to "break-downs," resulting from water, in the liquid form, passing into the cylinders along with the steam.
1828. A Method of "chucking" delicate Metal-work, in order that it may be turned with perfect truth
In fixing portions of work in the turning-lathe, one of the most important points to attend to is, that while they are held with sufficient firmness in order to be turned to the required form, they should be free from any strain which might in any way distort them. In strong and ponderous objects this can be easily accomplished by due care on the part of an intelligent workman. It is in operating by the lathe on delicate and flexible objects that the utmost care is requisite in the process of chucking, as they are easily strained out of shape by fastening them by screws and bolts, or suchlike ordinary means. This is especially the case with disc-like objects. As I had on several occasions to operate in the lathe with this class of work I contrived a method of chucking or holding them firm while receiving the required turning process, which has in all cases proved most handy and satisfactory.
This method consisted of tinning three, or, if need be, more parts of the work, and laying them down on a tinned face-plate or chuck, which had been heated so as just to cause the solder to flow. As soon as the solder is cooled and set, the chuck with its attached work may then be put in the lathe, and the work proceeded with until it is completed. By again heating the chuck, by laying upon it a piece of red-hot iron, the work, however delicate, can be simply lifted off, and will be found perfectly free from all distortion.
I have been the more particular in naming the use of three points of attachment to the chuck or face-plate, as that number is naturally free from any risk of distortion. I have on so many occasions found the great value of this simple yet most secure mode of fixing delicate work in the lathe, that I feel sure that any one able to appreciate its practical value will be highly pleased with the results of its employment.
The same means can, in many cases, be employed in fixing delicate work in the planing-machine. All that is requisite is to have a clean-planed wrought-iron or brass fixing-plate, to which the work in hand can be attached at a few suitable parts with soft solder, as in the case of the turning lathe above described.
1828. A Method of casting Specula for Reflecting Telescopes, so as to ensure perfect Freeness from Defects, at the same time enhancing the Brilliancy of the Alloy.
My father possessed a very excellent achromatic spy-glass of 2 inches diameter. The object-glass was made by the celebrated Ramsden. When I was about fifteen I used it to gaze at the moon, planets, and sun-spots. Although this instrument revealed to me the general characteristic details of these grand objects, my father gave me a wonderful account of what he had seen of the moon's surface by means of a powerful reflecting telescope of 12 inches diameter, made by Short— that justly celebrated pioneer of telescope making. It had been erected in a temporary observatory on the Calton Hill, Edinburgh. These descriptions of my father's so fired me with the desire to obtain a sight of the glorious objects in the heavens through a more powerful instrument than the spy-glass, that I determined to try and make a reflecting telescope which I hoped might in some degree satisfy my ardent desires.
I accordingly searched for the requisite practical instruction in the pages of the Encyclopedia Britannica, and in other books that professed to give the necessary technical information on the subject. I found, however, that the information given in books—at least in the books to which I had access was meagre and unsatisfactory. Nevertheless I set to work with all earnestness, and began by compounding the requisite alloy for casting a speculum of 8 inches diameter. This alloy consisted of 32 parts of copper, 15 parts of grain tin, and 1 part of white arsenic. These ingredients, when melted together, yielded a compound metal which possessed a high degree of brilliancy. Having made a wooden pattern for my intended 8-inch diameter speculum, and moulded it in sand, I cast this my first reflecting telescope speculum according to the best book instructions. I allowed my casting to cool in the mould in the slowest possible manner; for such is the excessive brittleness of this alloy (though composed of two of the toughest of metals) that in any sudden change of temperature, or want of due delicacy in handling it, it is very apt to give way, and a fracture more or less serious is sure to result. Even glass, brittle though it be, is strong in comparison with speculum metal of the above proportions, though, as I have said, it yields the most brilliant composition.
Notwithstanding the observance of all due care in respect of the annealing of the casting by slow cooling, and the utmost care and delicate handling of it in the process of grinding the surface into the requisite curve and smoothness suitable to receive the final polish,— I was on more than one occasion inexpressibly mortified by the sudden disruption and breaking up of my speculum. Thus many hours of anxious care and labour proved of no avail. I had to begin again and proceed da capo. I observed, however, that the surplus alloy that was left in the crucible, after I had cast my speculum, when again melted and poured out into a metal ingot mould, yielded a cake that, brittle though it might be, was yet strong in comparison with that of the speculum cast in the sand mould; and that it was also, judging from the fragments chipped from it, possessed of even a higher degree of brilliancy.
The happy thought occurred to me of substituting an open metal mould for the closed sand one. I soon had the metal mould ready for casting. It consisted of a base plate of cast iron, on the surface of which I placed a ring or hoop of iron turned to fully the diameter of the intended speculum, so as to anticipate the contraction of the alloy. The result of the very first trial of this simple metal mould was most satisfactory. It yielded me a very perfect casting: and it passed successively through the ordeal of the first rough grinding, and eventually through the processes of polishing, until in the end it exhibited a brilliancy that far exceeded that of the sand mould castings.