Grace's Guide To British Industrial History

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Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 147,919 pages of information and 233,587 images on early companies, their products and the people who designed and built them.

Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 147,919 pages of information and 233,587 images on early companies, their products and the people who designed and built them.

Life of Richard Trevithick by F. Trevithick: Volume 1: Chapter 10

From Graces Guide


Trevithick's High-Pressure Steam Puffer Engine, Erected at Tredegar Puddling Mill, 1801. (See key below)

June 22, 1854.

I enclose you a tracing of the old puddling engine we have here. I am sorry my young man could not get the motion complete, but as you have better draughtsmen you perhaps could get them to finish one from this. The centres of the parallel motion are all given, and the dimensions of the cog- wheels; there is no beam, only a cross-head, from which there is a connecting rod on each side of the cylinder, down to the crank of the driving wheel. The side beam of the parallel motion is a light casting.
Yours truly,


About the year 1800 Mr. Trevithick came to Penydarran to erect a forge-engine for the company. I was at this time over-looking the engines at Penydarran. I assisted Mr. Trevithick in the erection of the forge-engine. When this engine was finished Mr. Trevithick commenced the construction of a locomotive. She was used for bringing down metal from the furnaces to the old forge. After working for some time in this way, she took a journey of iron from Penydarran down the Basin Road. On the journey she broke a great many of the tram-plates. After this she was used as a stationary engine, and worked in this way several years. The boiler was made of wrought iron, having a breeches tube; the cylinder was about 41 inches in diameter; the steam pressure about 40 lbs. to the inch. The steam from the cylinder was discharged into the stack."[1]

26th December, 1868.

DEAR SIR, The mill and puddling engine at Tredegar were made by Mr. Aubry and my father at Penydarran. There was another at Llanelthy, near Abergavenny, and several about the collieries. My father was employed in Penydarran from 1800, when Mr. Trevithick put up the puddling engine and a blast-engine: there was also a winding engine worked by old William Richards; he continued to work it for forty years.
Yours truly,


P.S.— The Penydarran winding engine was taken down in 1855; the Penydarran puddling engine in 1854; the Tredegar puddling engine in 1856."[2]

The variety and practical perfection of mechanical combinations in Trevithick's patent of 1802 are in some measure due to his having before that time proved their suitability.

His Cornish high-pressure steam portable engines of 1798 and 1799 were extended to South Wales, one of which was erected about 1800 or 1801, for giving motion to the large hammer or rolls or other work in the puddling mill of Tredegar Iron Works; remaining at work in 1854, when Mr. Ellis gave an outline description of it.

Rees Jones, who worked as an engine-fitter at Penydarran in 1794, says that Trevithick erected a forge-engine there about the year 1800, and having finished it, commenced his locomotive tramroad-engine. This latter having worked for some time as a locomotive, was removed from the tramway and used as a stationary engine. The boiler was of wrought iron, with an internal breeches or return fire-tube, working with steam of 40 lbs, to the inch; discharging the waste steam into the stack.

Mr. Ellis' puddling engine at Tredegar, the Penydarran puddling engine, a blast-engine, a winding engine worked by William Richards for forty years, an engine erected at Llanelthy, and several about the collieries; these continued in constant use for fifty or more years.

The Tredegar puddling-mill high-pressure puffer-engine was comparatively of large size; the regulating cock and four-way cock, blast-pipe in the chimney, feed-pump, fire-place, and flues, are not shown by Mr. Ellis, and therefore I have not ventured to draw them. The practical engineer will readily discern the positions they occupied.

The wrought-iron fire-tube the steam pressure 50 lbs. to 100 lbs. to the square inch; the used steam "puffed through a blast-pipe, up the wrought-iron chimney, heating the feed-water in its passage through the feed- cistern;", the external boiler of four cast-iron cylinders bolted together, and a kind of box at one end, in which the cylinder was fixed; a cross-head and two side rods giving motion to the cranks, the piston-rod kept in its proper course by a rocking-beam parallel motion, are parts of a whole, not one of which is found in a Watt engine. In 1837 the writer lived near this engine, and frequently saw it at work; the blast was as useful as in the locomotives then in the writer's charge. The old engineman said it had never been altered since its first erection, and had never given any trouble or required any repairs worth mentioning, though working night and day; the boiler was easy to fire and gave plenty of steam; one engineman attended to the varying demands of power and steam supply. The same general principles may be traced in the drawing of the ‘Catch-me-who-can' of seven years later, the most marked difference being that the locomotive had piston-rod guides as they still have, while the puddling-mill engine had a rocking-beam parallel motion.

We have an account of a trial of a small high-pressure engine made in 1804, in Wales, to ascertain its powers to raise water. The cylinder was 8 inches in diameter, and 4.5 feet stroke. It worked a pump 18.5 inches in diameter, and 4.5 feet stroke, which raised water 28 feet high. It worked at the rate of eighteen strokes per minute, and consumed about 80 lbs. of coal per hour. This when reduced is about 17.5 million pounds raised 1 foot high for each bushel of coal.

Many provisions have been made to guard against the bursting of high-pressure steam-boilers by Mr. Trevithick, who first brought the high-pressure engines into use. At first he proposed enclosing the safety-valve in such a manner that no one could get access to it to increase the load beyond what was intended to be employed. Secondly, he drilled a hole in the boiler, which he plugged up with lead, at such a height from the bottom that the boiler could never boil dry without exposing the lead to be melted, and consequently making an opening for the steam to escape. [3]

The engine described by Rees was very similar to the locomotive referred to in Trevithick's letter as applicable to various purposes,[4] for locomotion or for pumping, working with 80 lbs. of steam to the inch, having a locked safety-valve, and soft-metal plug on the boiler. A portion of the boiler of one of those engines may be seen at the Kensington Museum.[5]

Mr. Crawshay believed that Trevithick's Welsh tramroad-engine had a wrought-iron boiler and two cylinders, and certainly such an engine was constructed at Penydarran about that time: whether or not it was first used as a locomotive, it worked for some twenty years as a hammer-mill engine, and then for about thirty years as a pumping or winding engine in sinking shafts in coal-mines, after which, in 1850, a plate was cut out of the wrought-iron boiler, having two holes which served for fixing the cylinders, clearly showing the use by Trevithick at that early date of double-cylinder engines.

Rees's account of one of Trevithick's high-pressure puffer engines erected in Wales to test its real and economical power as compared with the Watt low- pressure vacuum engine, shows that people did not believe Trevithick,[6] or comprehend his engines. They could trust in an atmospheric or a Watt condensing engine of large size and cost, but not in a small thing put together by inexperienced workmen. Trevithick replied, "I'll show you that it is so." The locomotive engine was turned into a pumping engine, that they might measure the work done. The economical duty of this high-pressure steam-engine as compared with the Watt low-pressure vacuum engine is spoken of in another chapter.[7] A small portable engine with an 8-inch cylinder and 4 feet 6 inch stroke worked a large pump of 18.5 inches in diameter and 4 feet 6 inch stroke, raising the water through a column 28 feet high; to perform this required a pressure of steam of from 80 to 100 lbs. on the inch in the cylindrical boiler.

In this history of sixty or seventy years ago, applying only to one field of Trevithick's labours, we have puddling-mill engines, forge-engines, blast-engines, winding engines, pumping engines, locomotives, planishing-hammer engines, and shaft-sinking engines, with boilers of wrought iron and of cast iron, giving steam up to 100 lbs. on the inch; double-cylinder vertical engines, and single-cylinder horizontal engines, working with beam and parallel motion or guides, with blast-pipe in the chimney — all more or less portable, and in no particular similar to the Watt engine.

While the foregoing was being carried out in Wales, high-pressure engines were also erected in other places.

  • 1803[8]
    • April 9th. To premium on Wm. Kinman’s 6-horse, charged at 4-horse . £50-8s-0d
    • May 2nd. Miller and May, 5-horse . . . . . £13-0s-0d
    • May 2nd. George Russell, 8-horse . . . . . . . £75-12s-0d
    • May 23rd. Jas. and Edwd. Sward, 8-horse . . . .£75-12s-0d
    • June 4th. Lloyd, 6-horse . . . . . . . . . . . £75-12s-0d
    • June 4th. Butt, Jamieson, and Co., 6-horse . . £75-12s-0d
    • June 4th. Anthony Harman, 3-horse . . . . . . .£7-5s-0d
    • May 2nd. Josias Spoils, 12-inch cylinder, for Staffordshire . . £150-0s-0d
    • May 23rd. T. Turton, Esq., 20-inch cylinder, to be erected in Staffordshire . . £315.0s-0d
    • May 28th. Lord Dudley and Ward, for a whimsey . . £420-0s-0d
    • June 6th. John Morris, Esq., a whimsey . . £262-10s-0d
    • Aug. 6th. General Bertham, for Deptford Dock-yard, 14-horse, to he erected as per agreement . . £750-0s-0d

In 1803 the Government adopted the new invention, Lord Dudley erected a high-pressure whimsey within sight of Soho, two others were erected in Staffordshire, and many of Trevithick's first high-pressure steam-engines were made at Coalbrookdale, Bridgenorth, and Stourbridge, not far from Soho.

The earliest of Mr. Watt's steam-engines giving rotatory movement were erected in 1784[9] those used the sun-and-planet wheel; and though the crank in a steam-engine had just then been patented, Watt's opposition to apply it in engines made at Soho caused its use in a steam-engine to be an unknown thing in Cornwall when Trevithick constructed his first high-pressure models with cranks. The difference between a low-pressure vacuum Watt rotatory engine and a high-pressure steam Trevithick was, that the former had stone foundations, beam and parallel motion, condenser and condensing water, and a large boiler. The latter had none of these things; it was self-contained and portable, and but one-third of the size or cost of the low-pressure of equal power.

Trevithick, Andrew Vivian, and William West were partners in the patent of 1802. Trevithick was the general correspondent, ready for all comers, promising advantages, talking away difficulties, and supplying engines from strange, untried workshops, to be paid for when convenient. Vivian was the commercial man. West was a sensible, steady-going mechanical man, ready to make good his promises to the letter, but somewhat obstinate. Such men under such circumstances could not continue to work in agreement. The large sphere of application of the high-pressure portable engine could not be grasped by three men destitute of workshops, or satisfactory means of construction or supply; and the patent laws were no better than a broken reed for support.

Vivian's account, to November, 1804, shows that in the short space of two years since the date of the patent they had received £1,250 as patent premium on the new high-pressure engines erected. The expenses had been £1,097, Mr. Samuel Homfray had apparently just joined the company.

Extracted from Andrew Vivian's accounts:-

  • DR.
    • Premiums received .. £1250
  • CR
    • 1804. Expenses • • £887-1s-7d
    • Nov. 25. By allowance for time to this day .. £100-0s-0d
    • Ditto. . By on account of disbursements since Mr. Homfray is concerned, to be settled next account £100-0s-0d
    • Ditto. . By Mr. Harvey, bill for a new cylinder, &c. . . .£9-18s-9d
    • Total . .£1,097-0s-4d
    • Balance .. £152-19s-8d
    • Total . .£1,250-0s-0d
  • Richard Trevithick two-fifths,
  • Andrew Vivian two-fifths,
  • William West one-fifth."

In May, 1805, Vivian was in London negotiating the sale of his share in the patent. Trevithick, then occupied in breaking away the rock in the Thames near Blackwall, was to give Sir William Curtis another offer of Vivian's share for £4,000, with an additional £1,000, if the threatened patent lawsuit with Dixon went in favour of the patentees.

May 22, 1805.

Dear Sir,— I have yours of the 18th instant, for which I am much obliged. It found me in a most melancholy situation. I returned from London here on Tuesday evening, between five and six o'clock, and found my poor Andrew much weaker than when I left him. He rejoiced to see me, but soon told me that we were soon to part to meet no more on earth and after taking the most affectionate leave of all, he said he had given up the world, and all that was therein, and resigned himself to will of that God who gave him life. About three or four o'clock the next morning the Almighty was pleased to take him. The dear boy was perfectly in his senses, and appeared to leave the world without pain. This has been a sad stroke to me, and have scarcely been able to write a letter since. My poor wife is still very unwell, and so is the infant child.

Had I not been so much in want of money at this present time, would not part with my share in the patent for the sum you have offered it at; but my circumstances at present oblige me to do what, in other circumstance, I would not.

If there is any risk at all in going to law with Dixon, why not avoid it? It is certainly very easy to make a friend of him, as the non-existence of the patent can be but of little consequence to him.

My finances at present oblige me to empower you to make another offer to Sir William Curtis that is, my share as it now stands, for £4,000, and to receive the other thousand if you succeed against Dixon. But should it not come to a trial, the last-mentioned thousand to be paid at the expiration of one year.

I have not seen my brother Henry since the receipt of yours, and shall write you on the other parts of your letter in a few days. And am, dear Sir,
Your most obedient servant,


Your dear family are all in good health. I hope my dear friend will do all in his power to serve me, and that if money cannot be obtained for my share, he will do his best endeavour to get about £2,000 some other way. Farewell.

Should you want my assistance on the Rock, I will willingly assist you merely as a friend, without sharing the profits.

July 1, 1805.

Dear Sir,— I have yours of the 27th instant, and am much grieved at the relation of all your distresses, and for my own part, will not agree to give that rascal Davey an inch; and must beg of you not to make it up but on very good terms, for I would rather lose £50 than the fellow should go unpunished. But shall leave it entirely to you, and have no objection to bring it into court again; but hope that will not keep you in town; if it is likely to, would rather you should make it up, but certainly he must pay very handsomely for your false imprisonment. You are a gentleman of too much consequence in the world to be trifled with, and your time must be valued high.

Your dear family are all well and anxious to see you, and mine also.

Dolcoath is better and better, but cannot say so of Binner Downs, though I believe more than paying cost. I suppose Cardell and Co. have a demand on us, but suppose that will be demanded through Edwards. I am not sorry that Rabey has given up the trial of the patent and I think it would be right for us to propose to refer the business of his demand and our set-off to some one, two, or three respectable persons. This you may do without advising with Mr. Homfray, as he is not concerned in this part of the dispute, and the other demand for patent premium may be left out of the present question. Pray give this a full thought, and act upon it as your better judgment may dictate. With hopes of hearing from, and seeing you soon,
I remain, dear Sir,
Your obedient servant,


Can you with any propriety say anything to Sir William Curtis about purchasing my share now Rabey has given up thoughts of attacking the patent?"

The difficult task of introducing a new thing was increased by legal questions in maintaining the patent right. Rascal Davey had had a trial with Trevithick, and put him in prison, but apparently on false grounds, and therefore ought to be made to pay handsomely for so trifling with a man of such great consequence to the world at large. Rabey also threatened to contest the patent right for the high-pressure steam-engines. Homfray was then an interested party, but Vivian thought Homfray had nothing to do with the particular engine on which Rabey had raised a question.

This was one of the weaknesses of so all-embracing a patent. The high-pressure steam-engine was new, and so were the particular engines drawn and described in the patent but Trevithick adapted them to all requirements, many of them of a form and detail not shown in the patent; such a course opened a door for litigation, even though the engines were covered by general terms in the patent, for such and similar purposes, and all on the principle of high steam.[10] Dixon refused to pay patent right, because "the words in Mr. Watt's specification are enough to indemnify him."

The supplying engines to all applicants, through numerous makers, and trusting to their honesty or judgment for payment of the patent premium, continued for a year or two longer, when, in 1807, Mr. Homfray, who had from the first Welsh experiments a watchful eye, if not a pecuniary interest, in Trevithick's labours, came forward as a leading shareholder, having bought Vivian's interest, and negotiated for Trevithick's.

The following papers, illustrating this arrangement, were kindly supplied by my friend Mr. Bennet Woodcroft.

May 31, 1807.

GENTLEMEN, On my return home I find your favour of the 25th inst. It’s impossible for me to say if Mr. Trevithick has done any act to encumber the Property he has in the engine concern, over which I hold the control by a deed of assignment.

"So far as concerns me I can have no objection to his disposing of his share, provided I am not injured, and placed in a worse situation. I have no wish whatever to prevent him from selling and making the most of his share. There is an account now not closed between me and him. which, by calling upon Mr. Bill, at No. 49, Rathbone Place, he can settle with Mr. Trevithick. There is likewise a note-of-hand of Mr. Trevithick I now hold for £300, dated 4th January, 1804, which I shall of course set-off against his account of patent-right as it comes due and I receive it. For any information you may wish respecting any legal forms necessary for the completion of Mr. Trevithick's sale, on my part I beg leave to refer you to Messrs. Strong, Still, and Strong, Lincoln's Inn.
I am, Gentlemen, Your most obedient servant,

(Signed) SAM. HOMFRAY.

N.B.— The account I believe is a small one, and easily adjusted; and the note-of-hand I could endorse to your clients, which they could charge to Mr. Trevithick as so much of the purchase-money, and they pay that sum to me.— S. H.

June 26, 1807.

Sir,— The transfer deed is ready for executing, and as it is necessary that you should put your signature to it, have sent it you for that purpose. Hope you will be so good as to execute it and forward it to Mr. West for his signature also. I owe you some patent premium, and wish to settle my account with you as early as possible, therefore would thank you to send me a copy of your account with me from the beginning, and authorize Mr. Bill to settle it with me on your behalf. Please to forward this business, as I am about to leave town.
I am, Sir, your very obedient servant,

(Signed) RD. THEVITHICK. Plough Inn, Kidney Stales, Limehouse.

September 11, 1807.

This is to certify that I have sold to you two-fifths of a sugar-mill, now on the premises of Mr. Geo. Bowdeys, Blackfriars Road, the above share being all my interest in it, for which I have received from you a valuable consideration.
I am, Sir, Your very humble servant,

Messrs. HAYNES AND DOUGLAS, Tottenham Court Road."

Samuel Homfray was an influential man of business in the Welsh Iron Works, and had taken an active part in the construction and trial of the Welsh locomotive and other of Trevithick's engines.

The accounts to February, 1807, show that the patent premiums received a little more than covered the expenses. To February, 1808, a profit of £254-15s-5d. was to be divided among four shareholders: Mr. Homfray, five-tenths; Mr. Trevithick, two-tenths; Mr. Bill, two-tenths; Mr. West, one-tenth. Andrew Vivian's share had been purchased by Mr. Bill.

Homfray went to various places to make the high-pressure engines known, lawyers' bills were paid, amounting to a quarter part of the whole premium-money received. Mr. Homfray hesitated to affix his name to the required legal documents and on his still declining, Trevithick sold to Messrs. Haynes and Douglas his two-fifth share of the patent in a sugar-mill.

April 23, 1808.

In a letter I have received from Mr. Bill, he mentions you have not received the letter I wrote from Messrs. Strong and Still's to you, which fully answered your wishes as to my not calling upon you for more money for supporting the patent than you had expressed to Mr. Bill, and which he mentioned to me. The letter answers every Purpose as though I had signed the deed. If you have not received it, some mistake must have happened, and if you will call at Messrs. Strong and Still's, they will show you the copy of it.

"I have an objection to the signing of deeds where a number of parties are concerned if it can be avoided (not more to this than any other), and especially where there appears no kind of necessity for my signing.

"From letters I have received from Mr. Bill, who is now on a journey, I am in hopes many engines will be ordered, and that we shall be put in a train of getting some return of money for the great trouble and expense I have been at in introducing the engines, which are now beginning to be generally understood. Our large engine here goes on wonderfully well; and at any time it suits your convenience to come into this part of the world, I shall be happy to show it you. I remain, Gentlemen,
Your most obedient servant,



24th September, 1805.

I feel some concern on account of the state of Mr. Bill's health, which, when he wrote last to me from Deal, was so indifferent that, by the advice of a physician, he was down there for sea-air; and he mentioned that if his health did not improve on his return to London in a week's time, that he thought he should decline the conduct of the engine concern. I have written several letters to him, and wished for some information in answer, and as he is silent, and the time of his return to London passed, I am fearful he is very ill. I therefore take the liberty of addressing you (being interested in the concern), and will be obliged by your informing me if Mr. Bill is in London, and if so, what state of health he is in; and if he has mentioned to you that he has thoughts of giving up the agency. I wish, likewise, you to say, if there is anything in the report of the Racing Engine being carried into effect, and if so, at what time, and the particulars of the bet, &c., as if it is to take place, I shall be very much inclined to see it. I have the satisfaction to say all the engines go extremely well; and the packing of our large engine has not been renewed for upwards of four months, and it is unknown how much longer it will go, it being now as good as new. By letting a small quantity of water drop constantly into the stuffing box, it runs down the rod upon the piston and keeps the packing moist. I have written this to Mr. Bill.
I am, Gentlemen, Your obedient servant,

(Signed) SAMUEL Homfray.
Messrs. HAYNES AND DOUGLAS, Tottenham Court Road, London

Such were the pecuniary and legal difficulties attending the introduction of even a good thing. Mr. Homfray was willing to share in the profits of the speculation, but disliked partnership, though he could not get on without Trevithick; while Mr. Bill failed to keep matters square, and wished to give up the agency.

Trevithick had not thought it worth while to inform his late friend of his having constructed the "Racing Engine" and London railway; and judging from the accounts, Trevithick, the inventor, and West, the ingenious workman, reaped the smallest share of profit for their largest share of the work.

In the six years following the date of the patent, from Mr. Bill's accounts, a hundred persons had used the new engine, comprising the Government, business companies, men of rank and influence, and men of science, living in various parts of England. Each particular engine required adaptation to its special work, and had to be constructed under every disadvantage of few-and-far-between manufactories, little better than what may now be seen in every small provincial town, and known as casting foundries.

Watt and Trevithick were rival engineers, working on totally different principles: the one constructed his engines so as to use the pressure of steam to expel the atmosphere, introducing it solely as a means of producing a vacuum as his motive power; whereas the other utilized the steam as a motor, and only used the vacuum when convenient.

Hyde Clarke, who knew Trevithick, and whose father was intimate with him, wrote:—

"The introduction of Trevithick's improvement gave increased power to steam, and it is of that importance that Stuart — no mean authority on historical points, and not likely, from national sympathy, to underrate low pressure, or overrate high pressure — is inclined to date the era of the steam-engine from this invention.[11] In the establishment of the locomotive, in the development of the powers of the Cornish engine, and in increasing the capabilities of the marine engine, there can be no doubt that Trevithick's exertions have given a far wider range to the dominion of the steam-engine than even the great and masterly improvements of James Watt effected in his day."

William West, in his disappointment at not being made rich by his share in the patent, became a clock and watch maker, and produced the best timekeepers in Cornwall, called West's chronometers; but he failed to comprehend Trevithick's account-keeping.

7th September, 1815.

SIR, Your ill-tempered letter I received, and think you conclude on very threatening terms. Now, sir, in the first instance, what right have you to make me debtor to you for £40 received of Wood and Murray? I hold a copy of your answer to them, saying you held no share in the patent at that time when they wrote to you respecting the engine, but recommended them to W. West, whom you sold a share to, saying Wm. West would license to erect engines on the patent. And as to Henry Vivian's charge, I shall not adhere to. I am fully satisfied that Mr. Babey paid his time and demand while employed about his engine; the £78 is double as much as he ought to have for what he performed. The part of patent money you allude to received from Mr. Rabey, I suppose is settled in our patent accounts, as I never received a single sixpence from the patent before that from Messrs. Wood and Murray; then I made a present of £1 to your children, because you refused making a charge for the drawing sent to Leeds, so I beg to remind you, in a comparative sense, you have heretofore been, like the caterpillars on the island of St. Helena, eating up the product of industrious labour; but as time has set free your demands of blunders from the command of law, I will guarantee to come forward, under bonds of word, to leave our account to arbitration, you appointing one and I appointing the other, whenever you like; and if I owe you any balance, I'll pay you, let it distress me as it may. Certainly it must distress my mind to think of paying for your blunders. Though I have no £20,000, I am not afraid to meet you, and if I have no thousands, I have no hundreds demanded on equal accounts, so I conclude in peace, and hope you'll be reconciled the same as an honest man.
Your humble,


The result to the active agents of this most comprehensive patent of 1802, making practical the high-pressure steam-engine and the locomotive, was years of labour without reward, annoyance and dread from ill-defined patent laws, and ill-will and loss of friendship between all the members, whose early acquaintance had led to mutual respect and esteem.

Foot Notes

  1. Recollections of Rees Jones, see 'Mining Journal,' October 2nd, 1858.
  2. Letter from Mr. Thomas Ellis, 4th March, 1869
  3. See Rees' 'Cyclopedia,' published 1819, under the word Steam-Engine.
  4. See Trevithick's February 20th, 1804, and March 4th, chap. ix.
  5. See chap. ix.
  6. See Trevithick's letter, August 22na, 1802, Chap. ix
  7. See chap. xx.
  8. Extract from Andrew Vivian's account-book.
  9. Mechanics' Magazine,' August 30th, 1823.
  10. See Trevithick's letter, January 5th, 1804, chap. xvii.
  11. Historical and Descriptive Anecdotes of the Steam-Engine,' by B. Stuart; 'Railway Register,' February, 1847; 'Railway Prejudices and Railway Progress,' by Hyde Clarke, Esq.

    • Detailed description of the Tredegar puddling-mill engine:—
    • a, the steam-cylinder, 2 ft. 4 in. diameter, 6-ft. stroke, fixed in the end of the boiler;
    • b, the piston-rod and cross-head;
    • c, supports for the radius-rod bolted to the boiler;
    • d, radius rods;
    • e, parallel-motion beam;
    • f, rocking beam;
    • g, cylindrical cast-iron boiler, 6 ft. 9 in. diameter, 20 ft. long, in pieces bolted together (the drawing shows the boiler a little shorter, to suit the paper);
    • h, chimney into which the waste steam is puffed as blast;
    • i, cistern for heating the feed-water, the blast-pipe going through on its way to the chimney;
    • j, foundation and stands for boiler and engine to bring it to the required level for the rolling-mill floor;
    • k, connecting or side rods:
    • l, cranks;
    • m, tooth-wheel, from which motion is given to fly-wheel shaft and machinery;
    • n, crank-shaft.
    • Note from Mr. Ellis:— The tube in the boiler was of wrought iron, 3 ft. in diameter at the fire-door end, becoming less in diameter from the bridge at the inner end of the fire-bars, turning back again at the other end of the boiler, and joining the chimney at the fire-door end, where it was 14 in. in diameter: the steam was worked at any pressure between 50 lbs. and 100 lbs. to the inch, and was puffed through a blast-pipe up the wrought-iron chimney, heating the feed-water in its passage through the feed-cistern. The steam was directed in the right channels by the four-way cock, and another cock served as a steam-regulator. This engine was taken down in 1856.

See Also