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.

The only remaining difficulty that I had to surmount was the risk of defects in the surface of the speculum. These sometimes result from the first splash of the melted metal as it is poured into the ring mould. The globules sometimes got oxidised before they became incorporated with the main body of the inflowing molten alloy: and dingy spots in the otherwise brilliant alloy were thus produced. I soon mastered this, the only remaining source of defect, by a very simple arrangement. In place of pouring the melted alloy direct into the ring mould, I attached to the side of it what I termed a "pouring pocket;" which communicated with an opening at the lower edge of the ring, and by a self-acting arrangement by which the mould plate was slightly tilted up, the influx of the molten alloy advanced in one unbroken tide. As soon as the entire surface of the mould plate was covered by the alloy, its weight overcame that of my up-tilting counterpoise, and allowed the entire apparatus to resume its exact level. The resulting speculum was, by these simple arrangements, absolutely perfect in soundness. It was a perfect casting, in all respects worthy of the care and labour which I invested in its future grinding and polishing, and enabled it to perform its glorious duties as the grand essential part of a noble reflecting telescope!

[Image]

A. Chill plate of cast iron turned to the curve of the speculum B. Turned hoop of wrought iron with opening at O. C. Pouring pocket. D. Counterpoise, By which the chill plate is tilted up The largest figure in the engraving is the annealing tub of cast iron filled with sawdust, where the speculum is placed to cool as slowly as possible.

The rationale of the strength of specula cast in this metal mould system, as compared with the treacherous brittleness of those cast in sand moulds, arises simply from the consolidation of the molten metal pool taking place first at the lower surface, next the metal base of the mould—the yet fluid alloy above satisfying the contractile requirements of that immediately beneath it; and so on in succession, until the last to consolidate is the top or upper stratum. Thus all risk of contractile tension, which is so dangerously eminent and inherent in the case of sand-mould castings, made of so exceedingly brittle an alloy as that of speculum metal, is entirely avoided. By the employment of these simple and effective improvements in the art of casting the specula for reflecting telescopes, and also by the contrivance and employment of mechanical means for grinding and polishing them, I at length completed my first 8-inch diameter speculum, and mounted it according to the Newtonian plan. I was most amply rewarded for all the anxious labour I had gone through in preparing it, by the glorious views it yielded me of the wonderful objects in the heavens at night. My enjoyment was in no small degree enhanced by the pleasure it gave to my father, and to many intimate friends. Amongst these was Sir David Brewster, who took a most lively and special interest in all my labours on this subject.

In later years I resumed my telescope making enjoyments, as a delightful and congenial relaxation from the ordinary run of my business occupations. I constructed several reflecting telescopes, of sizes from 10-inch to 20-inch diameter specula. I had also the pleasure of assisting other astronomical friends, by casting and grinding specula for them. Among these I may mention my late dear friend William Lassell, and my excellent friend Warren de la Rue, both of whom have indelibly recorded their names in the annals of astronomical science. I know of no subject connected with the pursuit of science which so abounds with exciting and delightful interest as that of constructing reflecting telescopes. It brings into play every principle of constructive art, with the inexpressibly glorious reward of a more intimate acquaintance with the sublime wonders of the heavens, I communicated in full detail all my improvements in the art of casting, grinding, and polishing the specula of reflecting telescopes, to the Literary and Philosophical Society of Manchester, illustrating my paper with many drawings. But as my paper was of considerable length, and as the illustrations would prove costly to engrave, it was not published in the Society's Transactions. They are still, however, kept in the library for reference by those who take a special interest in the subject.

1829. A Mode of transmitting Rotary Motion by means of a Flexible Shaft, formed of a Coiled Spiral Wire or Rod of Steel.

While assisting Mr. Maudslay in the execution of a special piece of machinery, in which it became necessary to have some holes drilled in rather inaccessible portions of the work in hand, and where the employment of the ordinary drill was impossible, it occurred to me that a flexible shaft, formed of a closely coiled spiral of steel wire, might enable us to transmit the requisite rotary motion to a drill attached to the end of this spiral shaft. Mr. Maudslay was much pleased with the notion, and I speedily put it in action by a close coiled spiral wire of about two feet in length.

This was found to transmit the requisite rotary motion to the drill at the end of the spiral with perfect and faithful efficiency. The difficulty was got over, to Mr. Maudslay's great satisfaction.

So far as I am aware, such a mode of transmitting rotary motion was new and original. The device was useful, and proved of essential service in other important applications. By a suitably close coiled spiral steel wire I have conveyed rotary motion quite round an obstacle, such as is indicated in the annexed figure.

[Image]

It has acted with perfect faithfulness from the winch handle at A to the drill at B. Any ingenious mechanic will be able to appreciate the value of such a flexible shaft in many applications. Four years ago I saw the same arrangement in action at a dentist's operating-room, when a drill was worked in the mouth of a patient to enable a decayed tooth to be stopped. It was said to be the last thing out in "Yankee notions." It was merely a replica of my flexible drill of 1829.

1829. A Mode of cutting Square or Hexgonal Collares Nuts or Bolt-Heads by means of a Revolving File or Cutter.

This method is refrered to, and drawings given, in the text, pp. 141, 142.

1829. A Investigation into the Origin and Mode of writing the Cuneiform Character

This will be found described in the next and final chapter

1836. A Machine for cutting the Key-Grooves in Metal Wheels and Belt Pulleys, of ANY Diameter.

The fastening of wheels and belt pulleys to shafts, so as to enable them to transmit rotary motion, is one of the most frequently-recurring processes in the construction of machinery. This is best effected by driving a slightly tapered iron or steel wedge, or "key" as it is technically termed, into a corresponding recess, or flat part of the shaft, so that the wheel and shaft thus become in effect one solid structure.

The old mode of cutting such key-grooves in the eyes of wheels was accomplished by the laborious and costly process of chipping and filing. Maudslay's mortising machine, which he contrived for the Block machinery, although intended originally to operate upon wood, contained all the essential principles and details required for acting on metals. Mr. Richard Roberts, by some excellent modifications, enabled it to mortise or cut out the key-grooves in metal wheels, and this method soon came into general use. This machine consisted of a vertical slide bar, to the lower end of which was attached the steel mortising tool, which received its requisite up and down motion from an adjustable crank, through a suitable arrangement of the gearing. The wheel to be operated upon was fixed to a slide-table, and gradually advanced, so as to cause the mortising tool to take successive cuts through the depth of the eye of the wheel, until the mortise or key-groove had attained its required depth.

The only drawback to this admirable machine was that its service was limited in respect to admitting wheels whose half diameter did not exceed the distance from the back of the jaw of the machine to the face of the mortise tool; so that to give to this machine the requisite rigidity and strength to resist the strain on the jaw, due to the mortising of the key-grooves, in wheels of say 6 feet diameter, a more massive and cumbrous frame work was required, which was most costly in space as well as in money.

In order to obviate this inconvenience, I designed an arrangement of a key-groove mortising machine. It was capable of operating upon wheels of any diameter, having no limit to it capacity in that respect. It was, at the same time, possessed in respect of the principle on which it was arranged, of the power of taking a much deeper cut, there being an entire absence of any source of springing or elasticity in its structure. This not only enabled the machine to perform its work with more rapidity, but also with more precision. Besides, it occupied much less space in the workshop, and did not cost above one-third of the machines formerly in use. It gave the highest satisfaction to those who availed themselves of its effective Services.

[Image]

A comparison of Fig. 1—which represents the general arrangement of the machine in use previous to the introduction of mine—with that of Fig. 2, may serve to convey some idea of their relative sizes. Fig. 1 shows a limit to the admission of wheels exceeding 6 feet diameter, Fig. 2 shows an unlimited capability in that respect.

1836. An Instrument for finding and marking the Centres of Cylindrical Rods or Bolts about to be turned on the Lathe.

One of the most numerous details in the structure of all classes of machines is the bolts which serve to hold the various parts together. As it is most important that each bolt fits perfectly the hole it belongs to, it is requisite that each bolt should, by the process of turning, be made perfectly cylindrical. In preparing such bolts, as they come from the forge, in order to undergo the process of turning, they have to be "centred;" that is, each end has to receive a hollow conical indent, which must agree with the axis of the bolt. To find this in the usual mode, by trial and frequent error, is a most tedious process, and consumes much valuable time of the workman as well as his lathe.

[Image]

In order to obviate the necessity for this costly process, I devised the simple instrument, a drawing of which is annexed. The use of this enabled any boy to find and mark with absolute exactness and rapidity the centres of each end of bolts, or suchlike objects. All that was required was to place the body of the bolt in the V-shaped supports, and to gently cause it to revolve, pressing it longitudinally against the steel-pointed marker, which scratched a neat small circle in the true centre or axis of the bolt. This small circle had its centre easily marked by the indent of a punch, and the work was thus ready for the lathe. This humble but really important process was accomplished with ease, rapidity, and great economy.

1836. Improvement in Steam-Engine Pistons, and in Water and Air-Pump Buckets, so as to lessen Friction and dispense with Packing.

The desire to make the pistons of steam-engines and air-pump buckets of condensing engines perfectly steam and water tight has led to the contrivance of many complex and costly constructions for the purpose of packing them. When we take a commonsense view of the subject, we find that in most cases the loss of power resulting from the extra friction neutralises the expected saving. This is especially the case with the air-pump bucket of a condensing steam-engine, as it is in reality much more a water than an air pump. But when it is constructed with a deep well-fitted bucket, entirely without packing, the loss sustained by such an insignificant amount of leakage as may occur from the want of packing is more than compensated by the saving of power resulting from the total absence of friction.

The first condensing steam-engine to which I applied an air-pump bucket, entirely without packing, was the forty horsepower engine, which I constructed for the Bridgewater Foundry. It answered its purpose so well that, after twenty years' constant working, the air-pump cover was taken off, out of curiosity, to examine the bucket, when it was found in perfect order. This system, in which I dispensed with the packing for air-pump buckets of condensing steam-engines, I have also applied to the pistons of the steam cylinders, especially those of high-pressure engines of the smaller vertical construction, the stroke of which is generally short and rapid. Provided the cylinder is bored true, and the piston is carefully fitted, and of a considerable depth in proportion to its diameter, such pistons will be found to perform perfectly all their functions, and with a total absence of friction as a direct result of the absence of packing. By the aid of our improved machine tools, cylinders can now be bored with such perfect accuracy, and the pistons be fitted to them with such absolute exactness, that the small quantity of water which the steam always deposits on the upper side of the piston, not only serves as a frictionless packing, but also serves as a lubricant of the most appropriate kind. I have applied the same kind of piston to ordinary water-pumps, with similar excellent results. In most cases of right packed pistons we spend a shilling—to save sixpence— a not unfrequent result of "so-called" refined improvements.

1836. An instantaneous Mode of producing graceful Curves, suitable for designing Vases and other graceful objects in Pottery and Glass.

The mode referred to consists in giving a rapid "switch" motion to a pencil upon a piece of paper, or a cardboard, or a smooth metal plate; and then cutting out the curve so produced, and employing it as a pattern or "template," to enable copies to be traced from it. When placed at equal distances, and at equal angles on each side of a central line, so as to secure perfect symmetry of form according to the nature of the required design, the beauty of these "instantaneous" curves, as I term them, arises from the entire absence of any sudden variation in their course. This is due to the momentum of the hand when "switching" the pencil at a high velocity over the paper. By such simple means was the beautiful curve produced, which is given on the following page. It was produced "in a twinkling," if I may use the term to express the rapidity with which it was "switched." The chief source of the gracefulness of these curves consists in the almost imperceptible manner in which they pass in their course from one degree of curvature into another. I have had the pleasure of showing this simple mode of producing graceful curves to several potters, who have turned the idea to good account. The illustrative figures on the next page have all been drawn from "templates" whose curves were "switched" in the manner of Fig. A.

[Image]

1836. A Machine for planing the smaller or detail parts of Machinery, whether Flat or Cylindrical.

Although the introduction of the planing machine into the workshops of mechanical engineers yielded results of the highest importance in perfecting and economising the production of machinery generally, yet, as the employment of these valuable machine tools was chiefly intended to assist in the execution of the larger parts of machine manufacture, a very considerable proportion of the detail parts still continued to be executed by hand labour, in which the chisel and the file were the chief instruments employed. The results were consequently very unsatisfactory, both as regards inaccuracy and costliness.

[image]

With the desire of rendering the valuable services of the Planing Machine applicable to the smallest detail parts of machine manufacture, I designed a simple and compact modification of it, such as should enable any attentive lad to execute all the detail parts of the machines in so unerring and perfect a manner as not only to rival the hand work of the most skilful mechanic, but also at such a reduced cost as to place the most active hand workman far into the background. The contrivance I refer to is usually known as "Nasmyth's Steam Arm." None but those who have had ample opportunities of watching the process of executing the detail parts of machines, can form a correct idea of the great amount of time that is practically wasted and unproductive, even when highly-skilled and careful workmen are employed. They have so frequently to stop working, in order to examine the work in hand, to use the straight edge, the square, or the calipers, to ascertain whether they are "working correctly." During that interval, the work is making no progress: and the loss of time on this account is not less than one-sixth of the working hours, and sometimes much more; though all this lost time is fully paid for in wages.

[Image] Apparatus for enabling the machine to execute segmented work

But by the employment of such a machine as I describe, even when placed under the superintendence of well-selected intelligent lads, in whom the faculty of good sight and nicety of handling is naturally in a high state of perfection, any deficiency in their physical strength is amply compensated by these self-acting machines. The factory engine supplies the labour or the element of Force, while the machines perform their work with practical perfection. The details of machinery are thus turned out with geometrical accuracy, and are in the highest sense fitted to perform their intended purposes.

1837. Solar Ray Origin of the form of the Egyptian Pyramids, Obelisks, etc.

This will be found described summarily in the next and final chapter.

1837. Method of reversing the action of Slide Lathes.

In the employment of Slide Turning Lathes, it is of great advantage to be able to reverse the motion of the Slide so as to enable the turning tool to cut towards the Head of the Lathe or away from it, and also to be able to arrest the motion of the Slide altogether, while all the other functions of the lathe are continued in action. All these objects are attained by the simple contrivance represented in the annexed illustration.

[Image]

It consists of a lever E, moving on a stud-pin S, attached to the back of the head stock of the lathe T. This lever carries two wheels of equal diameter marked B and G. These wheels can pitch into a corresponding wheel A, fixed on the back end of the lay spindle. When the handle of the lever E is depressed (as seen in the drawing) the wheel B is in gear with wheel A. while C is in gear with the slidescrew wheel D, and so moves the slide (say from the Head Stock of the lathe). On the other hand, when the lever E is elevated in position E", wheel B is taken out of gear with A, while G is put in gear with A, and B is put in gear with D; and thus the Slide is caused to move towards the Head Stock of the lathe. Again, where it is desired to arrest the motion of the Slide altogether, or for a time, as occasion may require, the lever handle is put into the intermediate position E', which entirely severs the communication between A and D, and so arrests the motion of the slide. This simple contrivance effectually served all its purposes, and was adopted by many machine tool-makers and engineers.

1838. Self-adjusting Bearings for the Shafts of Machinery

A frequent cause of undue friction and heating of rapidly rotating machinery arises from some inaccuracy or want of due parallelism between the rotating shaft or spindle and its bearing. This is occasioned in most cases by some accidental change in the level of the supports of the bearings. Many of the bearings are situated in dark places, and cannot be seen. There are others that are difficult of access—as in the case of bearings of screw-propeller shafts. Serious mischief may result before the heating of the bearing proclaims its dangerous condition. In some cases the timber work is set on fire, which may result in serious consequences.

In order to remove the cause of such serious mischief, I designed an arrangement of bearing, which enabled it, and the shaft working in it, to mutually accommodate themselves to each other under all circumstances, and thus to avoid the danger of a want of due and mutual parallelism in their respective axes. This arrangement consisted in giving to the exterior of the bearing a spherical form, so as, within moderate limits, to allow it to accommodate itself to any such changes in regard to mutual parallelism, as above referred to. In other cases, I employed what I may call Rocking centres, on which the Pedestal or "Plumber Block" rested; and thus supplied a self-adjusting means for obviating the evils resulting from any accidental change in the proper relative position of the shaft and its bearing. In all cases in which I introduced this arrangement, the results were most satisfactory.

In the case of the bearings of Blowing Fans, in which the rate of rotation is naturally excessive, a spherical resting-place for the bearings enabled them to keep perfectly cool at the highest speed. This was also the case in the driving apparatus for machine tools, which is generally fixed at a considerable height above the machine. These spherical or self-adjusting bearings were found of great service. The apparatus, being generally out of convenient reach, is apt to get out of order unless duly attended to. But, whether or not, the saving of friction is in itself a reason for the adoption of such bearings. This may appear a trifling technical matter of detail; but its great practical value must be my excuse for mentioning it.

1838. Invention of Safety Foundry Ladle.

The safety ladle is described in the text, p. 202.

1838. Invention of the Steam Ram

My invention was made at this early date, long before the attack by the steam-ram Merrimac upon the Cumberland, and other ships, in Hampton Roads, United States. I brought my plans and drawings under the notice of the Admiralty in 1845; but nothing was done for many years. Much had been accomplished in rendering our ships shot-proof by the application of iron plates; but it appeared to me that not one of them could exist above water after receiving on its side a single blow from an iron-plated steam-ram of 2000 tons. I said, in a letter to the Times, "As the grand object of naval warfare is the destruction by the most speedy mode of the ships of the enemy, why should we continue to attempt to attain this object by making small holes in the hull of the enemy when, by one single masterly crashing blow from a steam ram, we can crush in the side of any armour-plated ship, and let the water rush in through a hole, 'not perhaps as wide as a church door or as deep as a well, but 'twill serve'; and be certain to send her below water in a few minutes.* [footnote... In these days of armour-clad warships, when plates of enormous thickness are relied on as invulnerable, our Naval Constructors appear to forget that the actual structural strength of such ships depends on the backing of the plates, which, be it ever so thick, would yield to the cramming blow of a moderate-sized Ram. ...]

I published my description of the steam ram and its apparatus in the Times of January 1853, and again addressed the Editor on the subject in April 1862. General Sir John Burgoyne took up the subject, and addressed me in the note at the foot of this page.* [footnote... The following is the letter of General Sir John Burgoyne:

WAR OFFICE, PALL MALL, LONDON, 8th April 1862.

"General Sir John Burgoyne presents his compliments to Mr. Nasmyth, and was much pleased to find, by Mr. Nasmyth's letter in the Times of this day, certain impressions that he has held for some time confirmed by so good an authority. "A difficulty seems to be anticipated by many that a steamer used as a ram with high velocity, if impelled upon a heavy ship, would, by the revulsion of the sudden shock, be liable to have much of her gear thrown entirely out of order, parts displaced, and perhaps the boilers burst. Some judgment, however, may be formed on this point by a knowledge of whether such circumstances have occurred on ships suddenly grounding; and even so, it may be a question whether so great a velocity is necessary. "An accident occurred some twenty years ago, within Sir John Burgoyne's immediate cognisance, that has led him particularly to consider the great power of a ship acting as a ram. A somewhat heavy steamer went, by accident or mismanagement, end on to a very substantial wharf wall in Kingstown Harbour, Dublin Bay. Though the force of the blow was greatly checked through the measures taken for that purpose, and indeed so much so that the vessel itself suffered no very material injury, yet several of the massive granite stones of the facing were driven some inches in, showing the enormous force used upon them. "Superior speed will be very essential to the successful action of the ram; but by the above circumstance we may assume that even a moderate speed would enable great effects to be produced, at least on any comparatively weak point of even ironclad ships, such as the rudder." ...]

In June 1870, I received a letter from Sir E. J. Reed, containing the following extracts: —"I was aware previously that plans had been proposed for constructing unarmoured steam rams, but I was not acquainted with the fact that you had put forward so well-maturerd a scheme at so early a date; and it has given me much pleasure to find that such is the case. It has been a cause both of pleasure and surprise to me to find that so long ago you incorporated into a design almost all the features which we now regard as essential to ramming efficiency—twin screws and moderate dimensions for handiness, numerous water-tight divisions for safety, and special strengthenings at the bow. Facts such as these deserve to be put on record.... Meanwhile accept my congratulations on the great skill and foresight which your ram-design displays."

Collisions at sea unhappily afford ample evidence of the fatal efficiency of the ramming principle. Even ironclad ships have not been able to withstand the destructive effect. The Vanguard and the Kurfurst now lie at the bottom of the sea in consequence of an accidental "end-on" ram from a heavy ship going at a moderate velocity. High speed in a Steam Ram is only desirable when the attempt is made to overtake an enemy's ship; but not necessary for doing its destructive work. A crash on the thick plates of the strongest Ironclad, from a Ram of 2000 tons at the speed of four miles an hour, would drive them inwards with the most fatal results.

1839. Invention of the Steam Hammer, in its general principles and details.

Described in text, p. 231.

1839. Invention of the Floating Mortar or Torpedo Ram.

For particulars and details, see Report of Torpedo Committee.

1839. A Double-faced Wedge-shaped Sluice-Valve for Main Street Water-pipes.

The late Mr. Wicksteed, engineer of the East London Water Company, having stated to me the inconvenience which had been experienced from the defects in respect of water-tightness, as well as the difficulty of opening and closing the valves of the main water-pipes in the streets, I turned my attention to the subject. The result was my contrivance of a double-faced wedge-shaped sluice-valve, which combined the desirable property of perfect water-tightness with ease of opening and closing the valve.

This was effected by a screw which raised the valve from its bearings at the first partial turn of the screw, after which there was no further resistance or friction, except the trifling friction of the screw in its nut on the upper part of the sluice-valve. When screwed down again, it closed simultaneously the end of the entrance pipe and that of the exit pipe attached to the valve case in the most effective manner.

[image]

Mr. Wicksteed was so much pleased with the simplicity and efficiency of this valve that he had it applied to all the main pipes of his Company. When its advantages became known, I received many orders from other water companies, and the valves have since come into general use. The prefixed figure will convey a clear idea of the construction. The wedge form of the double-faced valve is conspicuous as the characteristic feature of the arrangement.* [footnote... At a meeting of the Institution of Civil Engineers, May 23, 1883, when various papers were read on Waterworks, Mr. H. I. Marten observed in the course of the discussion: —"It has been stated in Mr. Gamble's paper (on the waterworks of Port Elizabeth) that the sluice valves are of the usual pattern. The usual patterns of the present day are in wonderful advance of those of thirty or forty years since. The great improvement originated with the introduction of 'the double-faced sluice-cock.' This sluice-cock, which had now superseded every other description, was the creation of Mr. James Nasmyth's inventive genius. Mr. Marten said he well remembered the first reception of this useful invention, as he happened at that time to be a pupil of Mr. Thomas Wicksteed. He was present when Mr. Wicksteed explained to Mr. Nasmyth the want he had experienced of a sluice-cock for Waterworks purposes, which should shut and remain perfectly tight against a pressure coming from either side. Mr. Marten had a lively recollection of the instantaneous rapidity with which Mr. Nasmyth not only grasped but provided for the requirement; so that almost by the time Mr. Wicksteed had completed the statement of his want, Mr. Nasmyth had drawn upon the back of an old letter a rough sketch of the first double-faced sluice-cock; and in less than an hour had converted this rough sketch into a full-sized working drawing; in the preparation of which it fell to Mr. Marten's lot to have the honour to assist. In his 'Autobiography' Mr. Nasmyth referred to the conversation with Mr. Wicksteed, and introduced a print of the drawing made upon the occasion. The invention has been of the greatest use to the Waterworks Engineer, especially in connection with the constant supply system, in which it frequently happened that the pressure was sometimes against one face of the sluice-cock, and sometimes against the other."— See Proceedings and Discussions of the Institution of Civil Engineers, 1883, pp. 88, 89. ...]

1839. A Hydraulic Mattress Press, capable of exerting a pressure of Twenty thousand tons.

Being under the impression that there are many processes in the manufacturing arts, in which a perfectly controllable compressing power of vast potency might be serviceable, I many years ago prepared a design of an apparatus of a very simple and easily executed kind, which would supply such a desideratum. It was possessed of a range of compressing or squeezing power, which far surpassed anything of the kind that had been invented. As above said, it was perfectly controllable; so as either to yield the most gentle pressure, or to possess the power of compressing to upwards of twenty thousand tons; the only limit to its power being in the materials employed in its construction.

The principle of this enormously powerful compressing machine is similar to that of the Hydraulic Press; the difference consisting principally in the substitution of what I term a Hydraulic Mattress in place of the cylinder and ram of the ordinary hydraulic press. The Hydraulic Mattress consists of a square or circular water-tight vessel or flat bag formed of 1/2-inch thick iron or steel plates securely riveted together; its dimensions being, say 15 feet square by 3 feet deep, and having semicircular sides, which form enables the upper flat part of the Mattress to rise say to the extent of 6 inches, without any injury to the riveted joints, as such a rise or alteration of the normal form of the semicircular sides would be perfectly harmless, and not exceed their capability of returning to their normal curve when the 6-inch rise was no longer necessary, and the elevating pressure removed.

[image]

The action of this gigantic press is as follows. The Mattress A A having been filled with water, an additional quantity is supplied by a force pump, capable of forcing in water with a pressure of one ton to the square inch; thus acting on an available surface of at least 144 square feet surface—namely, that of the upper flat surface of the Mattress. It will be forced up by no less a pressure than twenty thousand tons, and transfer that enormous pressure to any article that is placed between the rising table of the press and the upper table. When any object less thick than the normal space is required to receive the pressure, the spare space must be filled with a suitable set of iron flat blocks, so as to subject the article to be pressed to the requisite power.

As before stated, there may be many processes in the manufacturing arts in which such an enormous pressure may be useful; and this can be accomplished with perfect ease and certainty. I trust that this account of the principles and construction of such a machine may suggest some employment worthy of its powers. In the general use of the Mattress press, it would be best to supply the pressure water from an accumulator, which should be kept constantly full by the action of suitable pumps worked by a small steam-engine. The great press would require the high-pressure water only now and then; so that it would not be necessary to wait for the small pump to supply the pressure water when the Mattress was required to be in action.

1840. A Tapping Square, or instrument by which Perfect Verticality of the Tapping of Screwed Holes is insured.

[image]

The letter X shows how Screws are frequently made when tapped in the old mode; the letter T as they are always made when the Tapping Square is employed.

1840. A Mode of turning Segmental Work in the Ordinary Lathe

In executing an order for twenty locomotive engines for the Great Western Railway Company, there was necessarily a repetition of detail parts. Many of them required the labour of the most skilful workmen, as the parts referred to did not admit of their being executed by the lathe or planing-machine in their ordinary mode of application. But the cost of their execution by hand labour was so great, and the risk of inaccuracy was so common (where extreme accuracy was essential), that I had recourse to the aid of special mechanical contrivances and machine tools for the purpose of getting over the difficulty. The annexed illustration has reference to only one class of objects in which I effected great saving in the production, as well as great accuracy in the work. It refers to a contrivance for producing by the turning-lathe the eighty bands of the eccentrics for these twenty engines. Being of a segmental form, but with a projection at each extremity, which rendered their production and finish impossible by the ordinary lathe, I bethought me of applying what is termed the mangle motion to the rim of a face plate of the lay, with so many pins in it as to give the required course of segmental motion for the turning tool to operate upon, between the projections C C in the illustration.

[image]

I availed myself of the limited to-and-fro horizontal motion of the shaft of the mangle motion wheel, as it, at each end of the row of pegs —in the face plate (when it passes from the exterior to the interior range of them) in giving the feed motion to the tool in; the slide rest, "turned" the segmental exterior of the eccentric hoops. This it did perfectly, as the change of position of the small shaft occurred at the exact time when the cut was at its termination,—that being the correct moment to give the tool "the feed, or advance for the taking of the next cut. The saving, in respect to time, was 10 to 1 in comparison with the same amount of work done by hand labour; while the "truth" or correctness of the work done by this handy little application of the turning-lathe was absolutely perfect I have been the more particular in my allusion to this contrivance, as it is applicable to any lathe, and can perform work which no lathe without it can accomplish. The unceasing industry of such machines is no small addition to their attractions, in respect to the production of unquestionably accurate work.

1843. Invention of the Steam Hammer Pile-driver.

Described in text, p. 261.

1843. A Universal Flexible Joint for Steam and Water-pipes.

[Image]

The chief novelty in this swivel joint is the manner in which the packing of the joints is completely enclosed, thereby rendering them perfectly and permanently watertight.

1844. An Improvement in Blowing Fans and their Bearings.

The principle on which Blowing Fans act, and to which they owe their efficiency, consists in their communicating Centrifugal action to the air within them.

In order to obtain the maximum force of blast, with the minimum expenditure of power, it is requisite so to form the outside rim of the Fan-case as that each compartment formed by the space between the ends of the blades of the Fan shall in its course of rotation possess an equal facility of exit for the passage of the air it is discharging. Thus, in a Fan with six blades, the space between the top of the blades and the case of the Fan should increase in area in the progressive ratios of 1-2-3-4-5-6.

[Image]

If a Fan be constructed on this common-sense principle, we shall secure the maximum of blast from the minimum of driving power. And not only so; but the humming sound—so disagreeable an accompaniment to the action of the Fans (being caused by the successive sudden escape of the air from each compartment as it comes opposite the space where it can discharge its confined block of air)—will be avoided. When the outer case of a Fan is formed on the expanding or spiral principle, as above described, all these important advantages will attend its use. As the inward current of air rushes in at the circular openings on each side of the Fan-case, and would thus oppose each other if there was a free communication between them, this is effectually obviated by forming the rotating portion of the fan by a disc of iron plate, which prevents the opposite in-rushing currents from interfering with each other, and at the same time supplies a most substantial means of fastening the blades, as they are conveniently riveted to this central disc. On the whole, this arrangement of machinery supplies a most effective "Noiseless Blowing Fan."

1845. A direct Action "Suction" Fan for the Ventilation of Coal-Mines.

The frequency of disastrous colliery explosions induced me to give my attention to an improved method for ventilating coal mines. The practice then was to employ a furnace, placed at the bottom of the upcast shaft of the coal-pit, to produce the necessary ventilation. This practice was highly riskful. It was dangerous as well as ineffective. It was also liable to total destruction when an explosion occurred, and the means of ventilation were thus lost when it was most urgently required. The ventilation of mines by a current of air forced by a Fan into the workings, had been proposed by a German named George Agricola, as far back as 1621. The arrangement is found figured in his work entitled De Re Metalicat, p. 162. But in all cases in which this system of forcing air through the workings and passages of a mine has been tried, it has invariably been found unsuccessful as a means of ventilation.

As all rotative Blowing Fans draw in the air at their centres, and expel it at their circumference, it occurred to me that if we were to make a communication between the upcast shaft of the mine and the centre or suctional part of the Fan closing the top of the upcast shaft, a Fan so arranged would draw out the foul air from the mine, and allow the fresh air to descend by the downcast shaft, and so traverse the workings. And as a Suction Fan so placed would be on the surface of the ground, and quite out of the way of any risk of injury—being open to view and inspection at all times—we should thus have an effective and trustworthy means for thorough ventilation.

[Image]

Having communicated the design for my Direct Action Suction Fan for coal-pit ventilation to the Earl Fitzwilliam, through his agent Mr. Hartop, in 1850, his lordship was so much pleased with it that I received an order for one of 14 feet diameter, for the purpose of ventilating; one of his largest coalpits. I arranged the steam-engine which gave motion to the large Fan, so as to be a part of it; and by placing the crank of the engine on the end of the Fan-shaft, the engine transferred its power to it in the most simple and direct manner. The high satisfaction which this Ventilating Fan gave to the Earl and to all connected with his coal-mines, led to my receiving orders for several of them.

I took out no patent for the invention, but sent drawings and descriptions to all whom I knew to be interested in coalmine ventilation. I read a paper on the subject, and exhibited the necessary drawings, at the meeting of the British Association at Ipswich in 1851. These were afterwards published in the Mining Journal. The consequence is that many of my Suction Ventilating Fans are now in successful action at home and abroad.

1845. An improvement in the Links of Chain Cables.



1845. An Improved Method of Welding Iron.

One of the most important processes in connection with the production of the details of machinery, and other purposes in which malleable iron is employed, is that termed welding, namely, when more or less complex forms are, so to speak, "built up" by the union of suitable portions of malleable iron united and incorporated with each other in the process of welding. This consists in heating the parts which we desire to unite to a white heat in a smith's forge fire, or in an air furnace, by means of which that peculiar adhesive "wax-like" capability; of sticking together is induced,—so that when the several parts are forcibly pressed into close contact by blows of a hammer, their union is rendered perfect.

But as the intense degree of heat which is requisite to induce this adhesive quality is accompanied by the production of a molten oxide of iron that clings tenaciously to the white-hot surfaces of the iron, the union will not be complete unless every particle of the adhesing molten scoriae is thoroughly discharged and driven out from between the surfaces we desire to unite by welding. If by any want of due care on the part of the smith, the surfaces be concave or have hollows in them, the scoriae will be sure to lurk in the recesses, and result in a defective welding of a most treacherous nature. Though the exterior may display no evidence of the existence of this fertile cause of failure, yet some undue or unexpected strain will rend and disclose the shut-up scoriae, and probably end in some fatal break-down. The annexed figures will perhaps serve to render my remarks on this truly important subject more clear to the reader.

[Image]

Fig.1 represents an imperfectly prepared surface of two pieces of malleable iron about to be welded. The result of their concavity of form is that the scoriae are almost certain to be shut up in the hollow part,—as the pieces will unite first at the edges and thus include the scoriae, which no amount of subsequent hammering will ever dislodge. They will remain lurking between, as seen in Fig.2. Happily, the means of obviating all such treacherous risks are as simple as they are thoroughly effective. All that has to be done to render their occurrence next to impossible is to give to the surfaces we desire to unite by welding a convex form as represented in Fig. 3; the result of which is that we thus provide an open door for the scoriae to escape from between the surfaces,—as these unite first in the centre, as due to the convex form, and then the union proceeds outwards, until every particle of scoriae is expelled, and the union is perfectly completed under the blows of the hammer or other compressing agency. Fig. 4 represents the final and perfect completion of the welding, which is effected by this common-sense and simple means,—that is, by giving the surfaces a convex form instead of a concave one.

When I was called by the Lords of the Admiralty in 1846 to serve on a Committee, the object of which was to investigate the causes of failure in the wrought-iron smith work of the navy, many sad instances came before us of accidents which had been caused by defective welding, especially in the vitally important articles of Anchors and Chain Cables. In the case of the occasional failure of chain cables, the cause was generally assigned to defective material; but circumstances led me to the conclusion that it was a question of workmanship or maltreatment of what I knew to be of excellent material. I therefore instituted a series of experiments which yielded conclusive evidence upon the subject; and which proved that defective welding was the main and chief cause of failure. In order to prove this, several apparently excellent cables were, by the aid of "the proving machine," pulled to pieces, link by link, and a careful record was kept of the nature of the fracture. The result was, that out of every 100 links pulled asunder 80 cases clearly exhibited defective welding; while only 20 were broken through the clear sound metal. This yielded a very important lesson to those specially concerned.

1845. Introduction of the V Anvil.

In connection with my Steam Hammer, when employed in forging great cylindrical shafts, I introduced what I termed my V anvil. Its employment has most importantly contributed to secure perfect soundness in such class of forgings.

In the old system of forging cylindrical shafts, the bar was placed upon a flat-faced anvil. The effect of each blow of the hammer upon the work was to knock the shaft into an oval form (see Fig. 1); and the inevitable result of a succession of such blows was destruction of the soundness of the centre or axis of the shaft.

[image]

In order to remedy this grave defect, arising from the employment of a flat-faced anvil, I introduced my V anvil face (see Fig. 2), the effect of which was, that the dispersive action of the blow of the hammer was changed into a converging action, which ensured the perfect soundness of the work; while the V or fork-like form of the angle face kept the work steadily under the centre of the hammer, allowing the scale or scoriae to fall into the apex or bottom of the V, which thus passed away, leaving the faces of the angle quite clear.

This simple and common-sense improvement was eagerly and generally adopted, and has been productive of most satisfactory and important results.

1847. A Spherical-seated Direct-weighted Safety Valve.

Having been on several occasions called to investigate the causes of steam boiler explosions, my attention was naturally directed to the condition of the Safety Valve. I found the construction of them in many cases to be defective in principle as well as in mechanical details; resulting chiefly from the employment of a conical form in the valve, which necessitated the use of a guide spindle to enable it to keep in correct relative position to its corresponding conical seat, as seen at A in Fig. 1. As this guide spindle is always liable to be clogged with the muddy deposit from the boiling water, which yields a very adhesive encrustation, the result is a very riskful tendency to impede the free action of the Safety Valve, and thereby prevent its serving its purpose.

[image]

With a view to remove all such causes of uncertainty in the action of this vitally important part of a steam boiler I designed a Safety Valve, having a spherical valve and corresponding seat, as seen in B C, Fig. 2. This form of Safety Valve had the important property of fitting to its bearing-seat in all positions, requiring no other guide than its own spherical seat to effect that essential purpose. And as the weight required to keep the valve closed until the exact desired maximum pressure of steam has been attained, is directly attached to the under side of the valve by the rod, the weight, by being inside the boiler, is placed out of reach from any attempt to tamper with it.