The Industries of Scotland: Their Rise, Progress and Present Condition
by David Bremner, 1869
Manufacture of Mineral Oils and Paraffin
The History of the Paraffin Manufacture - The Bathgate and West Calder Paraffin Works - Description of the Manufacturing Processes - Present Position of the Scotch Mineral Oil Trade
No branch of industry has risen more rapidly in Scotland than the manufacture of oils and other products from native shales, nor has any been brought to such a high degree of perfection within an equal time. Paraffin, which is so named on account of its want of affinity with most chemical substances, was discovered by Reichenbach in the year 1830, and about the same time by Dr Christison, of Edinburgh, acting without any knowledge of Reichenbach's investigations. After the discovery several patents were taken out for the making of oil from schistus or shale. In 1833 Butler's Specification describes the process for making oil from shale. Hompesch's Specification, dated 1841, describes the process of making oil from schist, clay-slate, and asphalt. Du Buisson's, dated 1845, describes the process of oil-making from the same material. Selligue, previous to 1845, distilled oils from the shales of Autun, in France.
In the year 1847 Professor Lyon Playfair, while visiting a brother- in-law who owned a coal-pit at Alfreton, Derbyshire, had his attention drawn to a thick, dark, oily fluid which trickled from rents in the roof of the colliery, and was struck by the idea that it might be transformed into some useful substance by proper chemical treatment. He imparted his views to Mr James Young, then a well-known chemist in Manchester, and suggested to that gentleman the advisability of subjecting the crude liquor to chemical investigation, with the view of testing the qualities it possessed. Mr Young took the hint, and, in the course of the experiments which he made, found that the crude fluid, on being distilled, yielded a pale yellow oil containing floating particles of lustrous matter, which, on subsequent examination, proved to be crystals of paraffin. Soon afterwards a factory for the distillation of burning and lubricating oils from the crude petroleum of the coal-mine was established at Alfreton by Mr Young. The enterprise was successful, and the new trade was prosecuted with vigour and energy; but the factory had not been in operation for two years when the supply of raw material ceased, and the works, which were expected to develop a new branch of manufacture, were brought to a stand. This untoward event had the effect of directing Mr Young's energies to the solution of a problem to which he had given much thought, and to the practical realisation of which he now looked for continuing the supply of oil so unexpectedly cut short. Observation and reflection had convinced him that the Alfreton petroleum was the product of very simple natural causes, and these he set himself to investigate. Guided by experience, he was led to the conclusion that the oil had its origin in the distillation of coal by subterranean heat. In the course of two years, during which he made many experiments, he was enabled to prove the correctness of the opinion he had formed. He found that, by distilling coal at a low temperature, he obtained a liquid of an oleaginous kind, similar in its virtue and consistency to the natural oil. The primary difficulties of the undertaking having been thus overcome, it became a question of pressing importance to decide whether the discovery could be made available for the purposes of trade. Unless it could be carried out so as to supply sufficient material for the stills of the manufactories, it was apparent that the discovery would be practically valueless. Subsequent experiments proved that the crude oil could be extracted from any coal of a bituminous nature, and that the largest quantity could be obtained from cannel coal. A suitable mineral, therefore, was all that was now required to bring the scheme into operation, and to obtain that the coal-fields were explored and their qualities tested.
Some bituminous coal obtained from Boghead, near Bathgate, in the county of Linlithgow, was tried by Mr Young in 1850, and found to be peculiarly rich in oil. As the supply was abundant, Mr Young, after taking out a patent for "treating bituminous coal to obtain paraffin and oil containing paraffin," was joined by Messrs Meldrum & Binney. They selected a site near the town of Bathgate, and erected thereon an extensive establishment for extracting oil from coal, and converting it into a variety of useful products. The works were put up under the superintendence of Mr Meldrum, and were conducted under his active management. Such was the beginning of a branch of trade which speedily assumed great importance, and converted the quiet town of Bathgate, together with the adjacent villages, into a great centre of industrial activity. The district was chiefly inhabited by hand-loom weavers, whose miserable earnings — in many cases not exceeding 4s. a-week — were barely sufficient to prevent starvation ; and when the new field of labour was opened up, the weavers gladly relinquished their looms, and sought employment at the paraffin works. A proof of the marvellous success that attended Mr Young's enterprise, and the deep hold that it took on the district, is afforded by the fact that, though the population of the parish and town of Bathgate had increased only from 2513 to 3341 between the years 1801 and 1851, the ten succeeding years witnessed an increase to 10,000. The manufactory was extended until it covered a great space of ground ; and the value of its products was recognised throughout the world.
Mr Young's patent expired in 1864, but previous to that time several works were in operation for distilling oil from shale. In the parish of West Calder a seam of shale lying on the limestone on the estate of Mr Hare of Calderhall was worked by Mr Gray, and the shale distilled at the Leavenseat Oil Works. About 1862 the West Calder Works were erected on the estate of Gavieside, by Messrs Fell & Co. About the same time Messrs Raeburn erected retorts at the Grange, on the estate of Charlesfield. In the parish of Mid-Calder the Oakbank Works were erected about 1863, on the estate of Mr Hare of Calderhall, by a limited liability company. In the parish of Uphall there are several extensive fields of shale. The Broxburn shales on the estate of the Earl of Buchan are leased by Mr Bell, who is most energetic in developing the mineral resources of that estate. About 1860 retorts were erected by Dr Steel of Wishaw at Broxburn, to distil oil from shale supplied by Mr Bell. Early in 1862 the Broxburn Shale Oil Company (Limited) was formed ; but after expending a large sum of money, it was wound up in about two years. The whole plant was sold, and Mr Fernie, of the Saltney Oil Works, succeeded the company in the occupation of the ground. After erecting upwards of 200 retorts, he sold his work to a company called the Glasgow Shale Oil Company (Limited). This company, as well as Mr Poynter at his works at Broxburn, are now producing large quantities of oil from shale supplied by Mr Bell. In addition to these works, Mr Bell has erected a large number of retorts; and Mr Hutchison has a small refinery at Broxburn. It will thus be seen that Broxburn is one of the most important seats of the oil trade. In the same pariah of Uphall there are extensive fields of shale on the estate of Mr M'Lagan, M.P. for the county of Linlithgow; and that gentleman erected retorts previous to the expiry of the coal oil patent in 1864. Shortly after the dissolution, in 1864, of the copartnery of Messrs E. Meldrum & Co. and of Messrs E. W. Binney & Co., the firms under which Young's patent was worked, Mr Meldrum became associated with Mr M'Lagan and Mr Simpson, of Benhar, in the Uphall Mineral Oil Company, which purchased the works on Mr M'Lagan's estate and leased his shale. Through the experience and skill of Mr Meldrum in the manufacture of paraffin oil, to which the prosperity of the Bathgate Chemical Company was so much due, the oil manufactured at the Uphall Works assumed at the first a position in the market second to none in the valuable points of burning quality, purity, and safety. The Uphall Works have recently been greatly extended, and are now the second largest in this country.
Since 1864 several oil-works have been erected, of which may be mentioned the Dundas Shale Oil Company, on the estate of Mr Dundas of Dundas, at Kirkliston ; the Westwood Shale Oil Company, on the estate of Captain Steuart; the Hermand Company, belonging to the Messrs Thornton, on the estate of Mr Maitland of Hermand — all of which manufacture the crude oil only.
After the partnership under which the Bathgate Chemical Works had been established was dissolved, Mr Young carried on the concern by himself for a year, during which time he conceived the idea of creating new works in the neighbourhood of West-Calder — a district particularly rich in bituminous shale. Having acquired necessary leases, &c., Mr Young chose a site on the estate of Addiewell, about a mile west from the village of West-Calder, and began the construction of an establishment on a more extensive scale than that at Bathgate. There was no accommodation in West-Calder for a large body of workpeople, and Mr Young's first care was to provide lodging for his workmen by building a range of houses. A bed of clay was discovered on the property, a brickwork was erected, and soon houses to the number of several hundreds were provided, the building of the manufactory being at the same time pushed forward. After considerable progress had been made, Mr Young organised a company to undertake the working of both the Bathgate and Addiewell establishments. The new copartnery, under the designation of Young's Paraffin Light and Mineral Oil Company (Limited), has been in existence for about three years, Mr Young, besides holding stock to a large amount, occupying the place of general manager. A brief description of the two manufactories of the company will convey some idea of their extent and importance.
The Bathgate Chemical Works are situated about a mile from the town. They occupy twenty-five acres of ground, and are connected with the main lines of railway in the vicinity by branch lines, which afford convenient conveyance for the raw material to any desired point, and for sending out the manufactured goods. The various departments are admirably arranged, and the appliances in all are so completely adapted to their purpose that it is difficult, after examining them, to believe that the manufacture of paraffin is really only a thing of yesterday. From a distance, the establishment has the appearance of a village of irregularly built grimy houses. A nearer view reveals a series of broad thoroughfares lined with retorts, stills, boilers, tanks, &c., some under iron roofs, and others exposed to the weather.
In order that he may understand what is going on around him, the visitor must begin at the coal-breaking shed. The coal used is a hard, rusty-black-coloured mineral. It is brought in from the pits in lumps of considerable size, and the first step in the process of manufacture is the breaking of these into small pieces, which may be conveniently shovelled into the retorts. There is a powerful crushing-machine for performing this part of the work. Contiguous to the breaking shed, the retorts, which are 200 in number, are ranged in sets of four each. The retorts are simply vertical cast-iron pipes twelve feet in length and fourteen inches in diameter. Each set of four retorts is built into a furnace, the lower part of the pipes being embedded in brickwork, while several feet of the upper end are left free. The retorts have funnel-shaped tops, and are fitted with air-tight stoppers. The lower extremity projects downwards through the furnace into a pit filled with water, an arrangement which, while it effectively shuts out the air, admits of the exhausted cinder being withdrawn without interruption. As the work goes on, the waste is withdrawn gradually, and fresh coal is added. The portion of the pipe which passes through the furnace is maintained at a dull red heat, and that is the point at which the distillation actually takes place. Under the influence of the fire, the coal is decomposed, the oil being driven off in the form of vapour, which is collected in a large main pipe having a connection with all the retorts. This main pipe conveys the oil vapour to the condensers, which are similar to those used in gas-works. The condensers stand outside, and, as the vapour passes through them, it is reduced to a liquid form. It is always found that a portion of the vapour is incondensable, and that portion is collected in a gas-holder, and is used for lighting the workshops. The liquid formed in the condensers is run off into a reservoir capable of containing 100,000 gallons. At this stage the oil has a black greasy appearance, like natural rock oil or petroleum, and gives off inflammable vapours at the usual atmospheric temperature. The tank is fitted with an airtight covering of iron for the purpose of restraining this vapour, and lessening the chances of its ignition. Another precaution against loss by fire consists of a large pipe inserted into the roof of the tank, and so arranged that, in the event of the oil taking fire, a strong jet of steam could be at once sent in, and the flames be thus extinguished.
The crude oil obtained by distilling the coal as described is subjected to various other processes, under which it yields four different products — namely, paraffin oil for burning, paraffin oil for lubricating machinery, a light volatile fluid called naphtha, and solid paraffin ; but before any separation of these takes place, the oil has to be thoroughly purified. It is first distilled, which is performed in a range of huge cylindrical stills, laid in a horizontal position. When the vapour from the stills is condensed, it is collected in tanks, and presents a wonderful improvement in appearance. The black sluggish stuff from the stock-tank has been converted into a dark-green limpid fluid. The impurities extracted from the crude oil are removed from the still after each charge. They form a large black lustrous substance, resembling coke, and make excellent fuel. Though much improved by the distillation, the oil is not yet sufficiently pure, and requires further treatment. It is run into circular iron tanks ; and, after a certain quantity of sulphuric acid is added, the liquid is violently agitated by a revolving stirrer. The acid has no affinity for the finer oil, but it has for the foreign substances which the oil holds in solution. At the end of four hours' agitation, the oil is seen to have become of a pale green colour; and on the liquid being allowed to settle, the vitriol and the organic impurities, by reason of their greater weight, collect in the bottom of the tank, and, when drawn off, this sediment is used for fuel. The oil is next transferred to a clean set of tanks, in which it is mixed with a strong solution of caustic soda, and again subjected to agitation. The soda neutralises any sulphuric acid that may remain in the oil, and rids it of impurities which were not affected by the vitriol. The oil is then distilled a second time, and the treatment with sulphuric acid and soda is repeated. After these operations, the oil presents a clear, pale, yellow colour, and in that condition it contains the elements of the four products mentioned above. To separate these, and make them available, is the next care of the oil-makers. This is accomplished by distilling the oil at various temperatures.
The first product taken off is naphtha, for the separation of which only a gentle heat is required. Naphtha is a valuable liquid,extensively employed in the arts, and as an illuminator. By raising the temperature of the stills after the naphtha vapour has passed off, paraffin oil is obtained. Before being ready for the market, both the naphtha and the oil are distilled separately, in order to make them perfectly pure. The oil is the most valuable and important of all the articles manufactured at Bathgate, and is extensively known for its illuminating qualities. In country districts, where gas is not manufactured, the paraffin oil has almost entirely superseded the other kinds of oil, and is universally admired for the clearness and brilliancy of the light which it affords. One gallon of the paraffin oil is equal in illuminating power to one and a quarter of American petroleum oil; and it can be produced at a price which gives a light cheaper than English coal gas. Another, and not the least important virtue which paraffin oil possesses, is the safety with which it can be used for domestic purposes. Great care is taken to separate the least trace of naphtha from it, so that there is no risk of explosion by accidental ignition.
When all the finer oil has been distilled over, the heat is increased, and a heavier vapour is driven off. This last produces a thick oil, which, when thoroughly cooled, assumes the consistency of grease. It is in reality a mixture of oil and solid paraffin. When the paraffin has been crystallised by cooling the liquid, it is separated from the oil by a process of nitration under pressure. The department in which the separation is accomplished is fitted up with hydraulic presses. The heavy oleaginous liquid is put into strong canvas bags, and these are placed in the hydraulic presses, and squeezed until all the oil is forced through the texture of the bags. The oil extracted in this way is an excellent fluid for lubricating machinery, and is largely used in cotton mills and other establishments in which machinery of a delicate kind is employed. Two valuable peculiarities of this oil are that it does not become rancid, and that it is free from all tendency to spontaneous combustion.
The solid paraffin is now the only substance left. After the oil is extracted, the paraffin is emptied out of the bags. It is then of a dirty-yellow colour, and requires a deal of purification before it assumes that beautiful wax-like appearance by which it is distinguished. The stuff is placed in iron vessels containing heated naphtha, by which it is dissolved. The naphtha acts on the impurities, and after a certain time the liquid is allowed to cool, when it again assumes a degree of consistency. It is then subjected to filtration in canvas bags as before. This operation of dissolving the paraffin in naphtha, cooling it, and filtering it through bags, is repeated until the substance has acquired the requisite whiteness and purity. On being taken from the filters for the last time, the paraffin is removed to a workshop in which it is subjected to the action of steam, which carries off the odour of the naphtha; and the paraffin, in a liquid state, is run into circular iron moulds, in which it solidifies. As thus finally purified and crystallised, the paraffin is a fine white substance, more transparent than wax, and of a beautiful lustrous structure. It lacks both taste and smell, burns with a white flame, without smoke. Candles made of it are in much favour, both on account of the brilliant light they afford and the clearness with which they burn.
The Addiewell Chemical Works occupy seventy acres of ground, fully one-third of which is covered by buildings, tanks, condensers, &c., while a large portion of the remainder is taken up by railways and roads which give access to all parts of the vast establishment. It is difficult to believe that the many buildings and peculiar-looking iron structures which stud the ground are parts of one concern, and that they are not a gathering of a dozen factories used for widely different purposes. The system of iron pipes which passes overhead, beneath the feet, and crops up in all quarters, would be sufficient, one would think, to carry the gas and water supply of a large town. The retort sheds, taken together, are upwards of 200 yards in length, and each contains a double row of retorts. The main pipe which collects the vapour from the retorts and conducts it to the condensers is nearly a yard in diameter. The condensers are on a like gigantic scale, each containing several miles of piping. As the processes at Addiewell are similar to those at Bathgate, it is unnecessary to explain them further. In addition to the four articles specified as being the chief products of the shale, a fifth substance of recent discovery has to be mentioned. It was discovered that the water which accompanies the oil through certain stages of the manufacture contained traces of ammonia, and by experiment it was found that the ammonia might be profitably extracted. There is now a special department for separating the ammonia, which is done by treating the water with sulphuric acid, and so producing sulphate of ammonia. This substance fetches L.16, 10s. a-ton, so that its preservation was well worthy of attention.
An interesting department of the Addiewell Works is that in which candles are made. Most persons are familiar with the beautiful candles made from Young's paraffin. They are to be found in every market of the world, and are manufactured in various parts of England and abroad, the paraffin being supplied from the works of the company in the large round cakes mentioned above. Before the discovery of these candles, Baron Liebig wrote:- "It would certainly be esteemed one of the greatest discoveries of the age, if any one could succeed in condensing coal gas into a white, dry, solid, odourless substance, portable and capable of being placed in a candlestick." The jury of the Great Exhibition of 1851 say:- "This very problem Mr Young appears to have accomplished, by distilling coal at a low temperature;" and they express an opinion that "the brilliant discoveries of Chevreul, but lately threatened by the splendour of the electric light, may be eclipsed by the general adoption of solidified coal-gas candles." Professor Hoffman, reporting for the jury of the Great Exhibition of 1862, describes "Mr Young as the founder of this industry," and speaks of the specimens exhibited " as realising the great problem which the rare sagacity of Liebig pointed out ten years ago." The candles are made by ingeniously devised machines, in which the paraffin, after being poured into the moulds is rapidly solidified by currents of cold water. Many hundredweights of candles are turned out weekly, though the department is the smallest in the establishment.
In the manufacture of paraffin, a great quantity of illuminating gas of a superior quality is produced. The town of Bathgate obtains its supply from the Paraffin Works, and the people of West- Calder have been considering the advisability of lighting their now rapidly increasing village with gas from Addiewell. It is a somewhat astounding fact that one and a quarter million cubic feet of gas are made every day at the Addiewell Works, for which, after subtracting what is necessary for lighting the establishment, no other use can be found than the heating of boilers and the like. It is stated that an offer was made by the company to supply the city of Edinburgh with gas at the rate of 1s. 6d. per thousand cubic feet.
The company's works at Bathgate are being supplied with raw material from the pits adjoining Addiewell, so that there is a constant traffic between the two places. Five locomotives are kept fully employed in the carrying department. Some of the pits lie close to the manufactory, and none of them are beyond a distance of two miles. The company have four hundred miners, and in the other departments upwards of a thousand persons are employed. A great part of the work is done by unskilled labourers, who receive from 16s. to 19s. a- week. There is a large staff of mechanics who execute most of the ironwork required ; and in addition to these there are joiners, masons, plumbers, and others who find constant occupation in the great but still growing place. The houses provided for the workpeople are commodious and comfortable, and they are let at very moderate rents. A school, under Government inspection, is also attached to the works.
Taken collectively, upwards of 3000 persons are employed in the Scotch mineral oil-works, and an immense sum of money has been invested in the several concerns. The trade recently experienced a period of depression, arising from the extensive importation of low- priced oils from America; but now that the public have had an opportunity of comparing the native with the foreign article, confidence in the former is being restored, and at no time during the past three or four years has the trade been in a more healthy state than now. Several of the oil-works which had been stopped for a time are in operation ; and on all sides extensions are in progress. Mr Young's little factory at Alfreton was the parent not only of the Scotch mineral oil trade, but also of that of America ; for until he began operations, oil had never been distilled to produce an article of commerce. The oil trade of Scotland is worth many hundreds of thousands of pounds annually, and that of America is estimated at ten millions. It has been rarely that an inventor has lived to see such a splendid outcome of his ideas, or to be a partaker, as Mr Young has been, of the wealth created by his discoveries. To any one who takes an intelligent interest in the manufacturing industries of the world, there could be few things more enjoyable than to walk over the great chemical manufactory at Addiewell in company with Mr Young, and hear him quietly relate, in answer to your queries, how he devoted himself to reveal some of the mysteries of nature, and convert to the use of mankind what were apparently the meanest among the contents of her storehouse. The story of Mr Young's life and labours is as interesting as almost anything to be found ill the whole range of industrial biography.