John Davie Morries Stirling
Inventor of a number of metallurgical improvements, including Stirling's Toughened Iron.
He was born John Davie Morries in 1810, the son of Jane Davie and Captain Andrew Morries (1779-1856) of the Royal Navy. He studied medicine at the University of Edinburgh, gaining his doctorate (MD) in 1831. He practised for some years in London plus a brief time in Norway. In 1854 he was living in Birmingham. He died on 21 October 1858, and is buried in the churchyard of Logie Kirk east of Stirling. On 7 May 1840 in Brighton he married the heiress Mary Wedderburn Stirling of Blackgrange. After their marriage he adopted the surname Stirling.
1846 Scottish patent granted to J. D. M. Stirling of Blackgrange, Scotland for certain new alloys and metallic compounds, with a method of welding the same and other metals. June 25.
1851 'ROYAL SCOTTISH SOCIETY OF ARTS . The tenth meeting of the session was held in the hall , 51 George Street, on Monday evening …..
On Iron and certain compounds and alloys of iron. By J. D. Morries Stirling , Esq.
Mr,. Stirling gave a concise description of the manufacture of cast-iron . The crude ore, coals, and flux ( which generally consists of bi-carbonate of lime ) , are thrown into the furnace in certain proportions and smelted , chiefly in this country by means of the hot-blast. Great prejudices at one time existed as to the hot-blast iron, but this was shown to he totally unfounded. A high authority on iron ( Hodgkinson ) had pronounced it to be as good as that smelted with the cold-blast ; and the simple fact is, that the hot-blast affords a great facility for running down inferior and almost irreducible ores , and hence the frequently inferior nature of hot-blast iron. So far as Mr Stirling's experience went, he considered the hot-blast iron—assuming that equally good ores were used—to be a purer and consequently a superior iron to that produced by the cold-blast . Mr Stirling alluded to the great improvement recently effected in the hot-blast by the application of the waste gases to this purpose , increasing the produce of some furnaces so much as three tons per day ; while at the same time, a superior quality of iron was obtained . Mr Stirling then described the different qualities of commercial pig-iron , and explained how it frequently occurred that an admixture of different sorts of ores produced the most superior iron . The same relation holds good in casting with different mixtures of iron —producing, even in this case, a superior quality of castings ; a fact well known to all ironfounders . Chemists he stated to be divided in their opinion as to the quantity of carbon contained in different descriptions of cast-iron ; and also in the different chrystalline structures exhibited in specimens from the same ore ; and that this could not arise from a greater or less proportion of carbon , he thought evident from the purely mechanical process of hardening chilled iron . Mr Stirling found that cast-iron may be rendered very tough without loosing its fusibility, by simply alloying it with malleable iron , in the proportion of thirty per cent . This was effected by two distinct operations of smelting ; the latter of these having the effect of completely incorporating the different particles , and constituting what he called " toughened cast-iron . " The increase of strength from this alloy he stated to be very great . A bar of ordinary cast-iron will only sustain a pressure of about 400 pounds per square inch transversely ; while this toughened iron will sustain in the same way a pressure of from 700 to 800 pounds per square inch ; thus indicating an increase of strength of about 100 per cent . At the same time, the tensile strength at the iron is doubled . A common ore broke with a weight of seven tons per square inch, while toughened iron required 12½ tons for the same result . These experiments were performed at Woolwich under the direction of the Government authorities. This improved iron was stated to be much less liable to corrosion, and, much easier converted into malleable iron by the operation of "puddling” than the ordinary sorts ; yielding , at the same time , a better, more fibrous , and stronger malleable iron . The addition of zinc, antimony, tin, and other metals , to iron , gave curious results in their different combinations. A large bell , for example , composed of one of these alloys, exhibited by Mr Stirling, gave out, when struck , a sonorous and prolonged intonation. Another of these alloys was considered valuable for railway purposes , more especially at the points of the rails , forming the angles of junction , and which, from the excessive friction, generally wear so fast . For such it had been successfully tried at Cowlairs. The same metals, in different proportions, produced a variety of alloys ; one which was capable of taking a high polish , was called "speculum metal ; " another , with copper and zinc for its basis, furnished a cheap description of bell-metal ; a third , with copper and manganese , produced an appearance equal to gold ; a fourth , with nickel and copper, a metal resembling silver ; and also the improved gunmetal of Mr Stirling, consisting of copper , zinc , and iron , which , on a comparative trial with the best guns at Woolwich , gave as the result of its increased resistance 16 tons to 11 of pressure per square inch of internal surface .
Mr Stirling exhibited a number of specimens , and was thanked by the chairman for his highly interesting communication. 
1852 The 'stupendous' viaduct for the joint MS&LR/LNWR goods station in Manchester had large cast iron girders supported by 28 cast iron Doric columns, designed by Alfred Stanistreet Jee.. All of the cast iron was of the toughened type patented by J. D. M. Stirling. The viaduct was demolished, but this 1912 photograph shows that at least the Doric columns survived.
1854 'In his specification, No. 472, of 1854, J. D. M. Stirling, of Birmingham, states that " Heretofore in the manufacture of tubes and cylinders of steel it has been usual to employ sheets of steel bent into the size and form desired, and then to join the edges by welding or brazing. Now, my invention consists of casting steel into tubular or hollow cylindrical forms, and then extending them in diameter or length, or both, by hammering, by drawing, or rolling, or by combining such processes. I cause cylindrical or tubular forms, of a length and diameter according to the length and diameter of tube or cylinder intended, to be cast of cast steel in a like manner to what has heretofore been practised when making tubes of copper or of brass, or solid ingots of cast steel, and it is found preferable to allow such steel castings to cool first; they are afterwards heated to the usual temperature at which cast steel is hammered, and I prefer tilting or hammering all such cylindrical or tubular forms previous to drawing brass tubes.'
1854 Advert: 'STIRLING’S PATENT IRON.
The toughened cast-iron for girders, SHAFTINGS, ROLLS, PINIONS, RAILWAY WAGGON WHEELS, ENGINE CYLINDERS, and for all purposes where strong dense iron is required, can be PROCURED of the following brands:—
LLOYD, FOSTER and Co.
RUSSELL'S HALL, &c.
RAILS of (or surfaced with) the PATENT HARDENED IRON, may be OBTAINED of the following makes :-
By direct applicatlon to the several Works.
'Full information as to Manufacture, Quality, and Terms for use of Patent Right, will be given by Mr. CHARLES MAY, 3, Great George Street, Westminster; and Mr. W. P. MARSHALL, 54 Newhall Street, Birmingham.
'Messrs. THORNTON and SONS, of BRADFORD STREET, BIRMINGHAM, RECEIVE ORDERS FOR Mr. MOTTIES STIRLING'S PATENT IRON RAILS, &c.'
'MR MORRIES STIRLING'S NEW METALLIC MIXTURES. From Chamber's Journal, June 1.
There are few things more remarkable than the total change of properties produced when two or more metals are made to combine together so as to form what are called alloys. This change is so marked, that it is often impossible to predict, from the known properties of the component metals, those of the alloy. We see this very distinctly in the long-known cases of brass, an alloy of copper and zinc, in all its varieties ; of bronze, bell-metal, gun-metal, and gong-metal, which are alloys of copper and tin; of type-metal, a mixture of lead, antimony, and tin; and many others.
'But although many useful and valuable alloys are known, when we consider the great number of simple metals—of which nearly fifty have been discovered, while at least twenty are sufficiently abundant to be applied to practical purposes ; and further, that any two metals may combine in many different proportions; and lastly, that very often an exceedingly, small proportion of one metal will give to another entirely new properties —when we consider these things, it is obvious that the existing alloys can form only a very small proportion of the immense number that may be obtained, many of which may probably turn out more valuable than any yet known.
'Mr. Morries Stirling, a gentleman thoroughly qualified for the task by a scientific education and long practical familiarity with chemistry, has, within these few years, paid much attention to the alloys, chiefly of the most important of all metals—iron. The results he has obtained are of the highest practical importance, and afford a signal proof of the truth of what we have stated—namely, that multitudes of valuable alloys remain to be discovered, and will richly reward the time and labour bestowed in such investigations. The reader is probably aware that the best hammered or malleable iron is nearly pure iron, and that cast-iron and steel are compounds - alloys they may almost be called - of iron with small proportions of carbon or charcoal. Cast-iron contains more carbon than steel, although in both the quantity is small, varying perhaps from ½ or 1 to 4 or 5 per cent. Cast-iron is fusible, hard, brittle, unelastic. Steel is also fusible and hard, but it is much tougher, and highly elastic. Here we see the powerful effects of so small a proportion of carbon ; for iron is nearly infusible, soft, and, very tough, when free from carbon.
'Now Mr. Stirling has found that cast-iron may be rendered very tough, without losing its fusibility, by simply alloying it with a certain proportion of wrought or malleable iron. He takes, we shall say, a quantity of any species of cast-iron—no matter for the general character of the results of what kind—and has it run from the blast-furnace into moulds containing a certain proportion of scrap-iron. The pigs thus formed are then melted, as usual, in a cupola, and run into the desired moulds for castings. Thus is produced what he calls his toughened cast-iron. His object, in the first experiments, was to improve the inferior, weaker, or more fluid irons to an equality with the better kinds ; but he did not expect the remarkable result actually obtained—namely, that all irons are thus brought to a kind of average strength and toughness far above the best cast iron. The strength of cast-iron is measured by the weight necessary to break a bar 1 square inch in section, and 4 feet 6 inches long between the supports, when suspended to the middle of the bar. The highest result obtained by Mr. Hodgkinson with the best (Blaenavon) cast-iron was 578 lbs.; but the average, as given by the same authority, is 454 lbs.
‘Now Mr. Stirling has obtained the very high result of 868 lbs.; while Mr Rennie, using Mr Stirling's method, obtained that above 900 lbs. Later experiments has given a still higher degree of improvement; so that the maximum increase of strength over that of average cast-iron (454 lbs.) is 120 per cent. ; and that which may on all occasions be calculated upon is 60 or 70 per cent., yielding an average of about 750lbs. as the breaking weight of an inch bar 4 feet 6 inches between supports. All sorts of cast-iron, if the due proportion of wrought scrap for each be ascertained, may be brought to this very high average of strength. Of course the improvement is, relatively to the original quality of the iron, not so great in the best as in the inferior sorts, but even in the best it is very great. This method is not a source of increased cost, for the cost is only greater in reference to the iron used. Thus Scotch pig-iron, at L.2 10s per ton, when the expense of the scrap-iron, besides the royalty of the patentee, is added to it, costs, as toughened cast-iron, about L.3 per ton. But it is now 60 per cent stronger than iron sold at L.3, 15s and L.4 per ton.
‘It is not easy to estimate the importance of this discovery, which has been confirmed by many of the leading iron masters, who are now using the patent under Mr Stirling's license. For all castings where strength is required, such as beams, girders, pillars, the advantage is so great and obvious, that it is hardly necessary to do more than allude to it. We obtain, at a cheaper rate, with the same weight of casting, nearly double the strength, which, for railway bridges, &c. is an invaluable result. But further, where the actual strength is more than sufficient to resist the strain to which it is exposed, we can attain that strength by using a much less weight of metal, and consequently at a still further reduced price.
‘Mr Stirling has produced an admirable alloy of iron, intended as a substitute for that of copper used for bells. It is, even under the patent, one-third cheaper than ordinary bell-metal, exceedingly hard, and not more brittle. It is wonderfully sonorous, and the tone of bells made of it (of which the writer possesses two) is superior to that of any bells of the same pitch we have ever heard. It is rich, full, musical, and pure, and singularly prolonged. Messrs Mears, the great London bell-founders, have taken a license for this alloy.
‘The same metals, in a different proportion, yield an alloy which takes a remarkably high polish and silvery lustre, and will probably le found advantageous for speculum metal.
‘There is another alloy of iron with one or more of the metals above-mentioned in certain proportions, designed for gun-metal. It is made of different qualities, according to the purpose for which it is intended. The tensile strength of two of the kinds was compared with that of gun-metal made at Woolwich. The metals were cast and tried under similar circumstances. Of the Woolwich gun-metal, the average of many sorts was 11 tons per square inch; while that of Mr Stirling's gun-metals was 16 tons per square inch.
‘With zinc for a basis, Mr Stirling has made many alloys of admirable properties. One, with an adjunct of copper, makes excellent bell metal. Another, with manganese besides copper, produces one having many of the qualities of gold. A third, with nickel and copper, furnishes a metal resembling silver. The second of these is found highly suitable for metal pens. It is gratifying to consider these discoveries as the result of diligent application to experiment, and to learn that the merits of the discoverer are likely to be duly rewarded. We find that his improved irons have obtained the approbation of the government commissioners for investigating the properties of iron for railway purposes.'
Sources of Information
-  Wikipedia
- Mechanics Magazine, Volume 45
- The Scotsman - Wednesday 16 April 1851
- Illustrated London News - Saturday 11 January 1851
-  'The Manufacture of Iron and Steel Tubes' by Edward Charles Robert Marks, 1903
- Birmingham Journal - Saturday 6 May 1854
-  Geelong Advertiser, 28 September 1850
-  'On the Application of Cast and Wrought Iron to Building Purposes' by William Fairbairn, 3rd Edition, 1864, p.64ff.