WELCOME TO THE BLOG SITE OF FLAMENCLORICO: LORE OF THE MINERS / PASIÓN FLAMENCA

We send a most sincere “gracias” to the Welsh Miners Lamps company for sending us a replica of an old-time miner’s lamp.  We received it this week and are very, VERY impressed with its authenticity. 

They have an array of very fabulous miner’s lamps available at their on-line store.  See here for their inventory: http://welshminerslamps.com/miners_lamps_medsize.shtml and http://www.welshminerslamps.com/miners_lamps_fullsize.shtml 

Safety Lamps - Past and Present

In the early days of mining in the United Kingdom, resinous bunches were used for lighting the outcrop workings. In these early days there was little, if any, circulation of air in the workings so the dangers from explosions, due to firedamp, were not great, owing to the fact that marsh gas requires a certain proportion of air before it becomes explosive. On the continent, earthen oil lamps were used at first, until the fear of explosions led to the use of dried fish skins from which a faint phosphorescence was emitted. It is obvious, however, that such a method must have led to mining work being carried on practically without light.

Tallow candles were subsequently used both for the works and for searching out gas. A small candle (30 to 40 to the lb.) was carried in a wet lump of clay - the flame reduced in size by placing clay at its lower extremity near the exposed portion of the wick according to Caleb Pamely’s “Colliery Managers’ Handbook.” The candle was raised from the floor very gradually in an upright position with one hand of the observer’s palm held outwards towards the light to shield it entirely from view except the very tip of the flame.  As it was raised, an appearance of ‘top’ or ‘cap’ of blue flame above the candle flame indicated the presence of gas in the air. As soon as this appeared the candle would be gently lowered, the searcher would withdraw with as little disturbance as possible, and the gaseous mixture dispersed as safely as possible. Where the quantity of gas was small it might be waved away with a coat or piece of brattice cloth. Before com­mencing to do this, the men would retire to a distance, away from the outgoing currents, his candle left out of the passing firedamp.

Another method of eliminating a small quantity of gas was to set fire to it. A special operator or ‘fireman’ with tremendous nerve did this at night. Protective attire might consist of wool, or leather, well damped, with the man’s face and head protected by a mask or hood. Using a long stick with a lighted candle attached to the end, he would crawl the last few yards toward the explosive gas, his head and body close to the floor. Immediately afterwards he would stand upright (or as much as the space would allow) to avoid the carbonic acid gas left by the explosion. The name ‘fireman’ has been retained to the present day for the men who search for gas. In some countries, he was called the ‘penitent’, on account of the resemblance of his dress to certain religious orders in the Roman Catholic Church. In many instances, in spite of all precautions, the fireman did not survive the explosion.

The first apparatus for producing light was Spedding’s ‘Steel Mill,’ patented in 1760. It consisted of a spur wheel and steel disc placed in a small steel frame, at the end of which the operator held a piece of flint. The continuous succession of sparks emitted by the rotation of the disc against the flint gave warning of danger by indicating the presence of firedamp. The faith in the ‘Mill’ was immediately shattered by a serious explosion at the Wallsend Colliery in 1785.

About this time attempts were made to light collieries by sunlight reflected by mirrors down the shaft.

The first attempt to use a lamp was made by Humboldt in 1798, but it would not burn in the presence of impure air and was therefore of no use in a coal mine.

The first person to demonstrate that a steady light could be employed in coal mines without the danger of external explosion, was Dr. William Reid Clanny, of Sunderland. On May 20th, 1813, he announced his discovery at a meeting at the Royal Society of Arts in London, when he presented the Society with the first miner’s ‘Safety Lamp’.

The first colliery in which a safety lamp was used was the Herrington Mill Pit, now the property of the Earl of Durham. The date was October 16th, 1815. It was Dr. Clanny’s modification of his first safety lamp. For this lamp he was awarded a medal by the Society of Arts in May 1816. In 1848, two years before his death, he was presented with a public testimonial in recognition of his services as the constructor and inventor of the very first safety lamp. This lamp consisted of a metal case containing a candle. It was fitted with a semicircular glass, and the air was fed by a pair of bellows.

The first oil-burning, safety lamp, utilizing gauze cylinders, was invented by Sir Humphrey Davy. He never claimed to be the inventor of the Miners’ Safety Lamp. In fact, on November 9th, 1815, when announcing to the Royal Society his discoveries on the nature and properties of firedamp, he gave a description of Clanny’s lamp, which he had seen in use at a northern colliery. He described it as ‘an ingenious arrangement for burning a candle supplied with atmospherical air by a bellows through water’. The first Davy Lamp was tried at Hebburn Colliery, January lst, 1816. Strictly speaking, the ‘Davy’ is not a lamp but a scientific instrument for detecting the presence of firedamp. All lamps of the present day embrace the principles of the Clanny and the Davy.

The first lamp made for George Stephenson was tried at Killing­worth Colliery, Northumberland, October 21st, 1815. It was a com­parative failure. Stephenson’s third lamp was more successful, and on December 21st, 1815, he exhibited it to a number of colliery owners and officials at the Literary and Philosophical Institute, Newcastle upon Tyne. Gratification at this success was checked when he learned that Davy had also entered the field. Davy was the competitor he feared. Stephenson did not hesitate to adopt Davy’s idea of the gauze cylinder nor did he regard it as piracy. In his pamphlet entitled ‘A Description of the Safety Lamp invented by George Stephenson’, published in 1817, he states that he regarded the substitution of a ‘gauze cylinder for a perforated case’ as ‘merely a variation in construction’. Nor was he inclined to give Davy much credit for his discovery, declaring that ‘the person who first constructed the perforated tin can lanthron in common use may, with great justice, claim the merit of having surrounded flame with a substance less liable to injury than glass’, which he subsequently produced as the ‘Improved Stephenson’, or ‘Geordie’. This lamp was practically a Davy Lamp with a glass cylinder inside the gauze. Indeed, the Royal Commissioners, in their report dated March 15th, 1896, stated, ‘if the glass breaks the Stephenson Lamp becomes a Davy’. The ‘Davy’ and ‘Geordie’ have long since been relegated to the list of obsolete lamps.

Stephenson, however, frankly admitted his indebtedness to Dr. Clanny. In his pamphlet already referred to, he states, ‘There can be no question upon the merit of the discovery, as there is no doubt that Dr. Clanny directed his talents to the subject and had constructed his original lamp, before I had reduced my ideas into practice.’

Continuing his experiments, and following up Davy’s discoveries, Dr. Clanny, in conjunction with the late John Mills, to whom he granted the sole right of manufacture, eventually produced his ‘lmproved Clanny Lamp’. He adopted gauze cylinders but made them 2 inches shorter than Davy’s. He used a circular glass for surrounding the flame, but made it 3 inches shorter than Stephenson’s.

Improved scientific methods of ventilation so greatly increased the velocity of air currents in coal mines, that in course of time, neither the Davy, Clanny, nor Stephenson lamps proved of practical ability in currents exceeding 400 to 800 feet per minute. In some cases their employment provided an element of danger, for among miners and officials there prevailed considerable ignorance on the question of noxious gas and the principles of the safety lamp. Thus it happened that for several years after the introduction of safety lamps explosions in coal mines were more frequent and more disastrous than they had ever been before. In Belgium and France, where the mines are deep and fiery, Governments made the use of safety lamps a question for the state, and they appointed Commissioners to decide the merits of the various lamps then in use. Both Governments decided in favor of the Mueseler, and the use of other kinds was prohibited. This, how­ever, did not prevent the recurrence of appalling disasters, and the Mueseler, it was found, was in certain circumstances, a more dangerous lamp than some of those it superseded. The Mueseler is a form of the Clanny with a chimney inside the gauze.

In 1884, the British Government appointed a Royal Commission, ‘To inquire into accidents in mines, and the possible means of preventing their recurrence or limiting their disastrous consequences’. In the course of their investigation, they found that ‘at least 60 per cent of the average of the deaths resulting from accidents in connection with coal mines were caused by explosions of firedamp and from falls from the roof and sides’. It was clearly proved that, to a large extent, these disasters were due to the inefficiency, or to the defective construction of safety lamps. The committee, therefore, ‘considered it their duty to give special attention to the subject of safety lamps’.

The Commissioners resolved, to test, practically, every form of safety lamp then in use, and to decide which, in their opinion, most nearly fulfilled the essential qualifications. For this purpose they invited makers, inventors, and users of safety lamps in the United Kingdom, Belgium, France, and Germany to send them lamps to be tested and reported on. In response, more than 250 lamps were sent in. Mr. Ellis Lever, realizing the importance of the task which the Commissioners had undertaken, offered a prize of 500 Pds Stlg for ‘the best safety lamp’, the tests to be conducted at Woolwich Arsenal by a specially selected committee which included several members of the Royal Commission.

The principle which guided the Royal Commission was that adopted by the Belgian and French Governments - viz., that the safest lamp was that which would most effectually withstand the influence of a strong current of explosive air.

Before the Commissioners, or the Woolwich Arsenal Committee, had concluded their tests, a French mining engineer (M. J. B. Marsuat) proved, by a series of elaborate experiments, that the principle was entirely wrong. He clearly demonstrated that, as there was no uniform velocity in the air-currents of a mine, a lamp constructed to burn safely in a strong current was a source of extreme danger when used in a stagnant atmosphere of explosive gas. His experiments proved that the gas entered the lamp, and remained there till the lamp was again brought in to a current sufficiently strong to force it through. The confined volume of gas then ignited and caused an explosion. This, M. Marsuat stated, ‘is an important key to certain accidents, hitherto ignored, assuredly very disquieting and which gives a key to certain accidents which have been difficult to explain’.

The Royal Commissioners frankly admitted their mistake. In their report (page 87) they stated: ‘The experiments conducted by M. Marsuat were so complete and so thoroughly established the truth of his observations that we thought it unnecessary to undertake a fresh investigation of the subject on an extended scale. We have, however, repeated a few of his experiments, and the results are in general accord with those obtained by him.’ Thus the Royal Commission and the Woolwich Arsenal Committee found no lamp then in use entirely fulfilled the essential qualifications they had established. The 500 Pds Stlg was not awarded.
 
The Royal Commissioners, however, finally decided in favor of four lamps, ‘in which the quality of safety, in a preeminent degree, is combined with simplicity of construction, and with illuminating power at least fully equal to that of the lamps hitherto in general use. These four lamps were: Gray’s Lamp, Evan Thomas No. 7, Marsuat, and Meuseler Bonneted. In our experiments the No. 7 has given, upon the whole, the best results.’

They reported, however, that the use of the ‘Mueseler’ was attended with a certain amount of danger so ‘care must be taken to avoid a considerable inclination from the vertical direction, …. but with the Marsuat’ they stated, ‘there is no probability of the flame being ex­tinguished under any circumstances attending ordinary use’. These statements were fully substantiated by the Woolwich Arsenal Com­mittee. On the recommendation of the Royal Commissioners certain improvements were made in the ‘Marsuat’ Lamps, viz., in the locking of the lamp’s bottom and in fixing of the case. The illuminating power of the ‘Marsuat’ exceeds that of other kinds burning animal or vegetable oil. 

An analysis of the Commissioners’ report shows that, though 250-300 lamps were tested, they had all, in a greater or a lesser degree, essential points of resemblance. They classified the oil burning lamps under six types, three English and three Belgian. The English types were the ‘Davy’, ‘Stephenson’ and ‘Clanny’; the Belgian types were the ‘Mueseler’, ‘Boty’ and ‘Eloin’. Of the ‘Eloin’ (patented in 1850), they reported ‘it is closely allied to the ‘Stephenson’ Lamp; of the original ‘Boty’ (adopted in 1 881 by the Belgian Government) they stated ‘it is a Clanny Lamp in general form’; and of the ‘Mueseler’ they reported ‘it is derived from the ‘Clanny”. Thus the safety lamps used so extensively on the Continent, at that time, were all adaptations of the three original English types.
 
A thoroughly efficient safety lamp is not a mere mechanical contrivance for giving light in a coal mine. It is an instrument con­structed in accordance with established laws of physical science. It ensures the burning of a protected flame in the presence of explosive gas, by regulating the necessary supply of atmospheric air, and by allowing the products of combustion to pass through without igniting the gaseous atmosphere. If the atmosphere is so heavily charged that noxious gas enters the lamp, its presence will be indicated by a change in the length and color of the flame, and (unless there are exceptional circumstances), the miner has sufficient warning to secure his safety.
 
The principles on which a thoroughly efficient safety lamp is constructed are practical, not theoretical. The component parts must all be in direct ratio. This ratio has been so accurately determined by practical tests, that any deviation from the established standards will adversely affect either the illuminating capacity of the lamp or its value as an indicator of danger. The reports of the Royal Commissioners on ‘Accidents in Mines’ (1886) and the Woolwich Arsenal Committee, show, however, that several inventors, and makers, who sent safety lamps for testing, or in competition, were either wholly ignorant of this fact and of the laws of physical science, or they did not regard them as of any importance.
 
The most flagrant deviation from established standards was in the case of the ‘Scotch Davy’, a lamp made in direct violation of the laws of physical science. Sir Humphrey Davy stated, as the result of pro­tracted experiments, that ‘when a cylindrical gauze is used, it should not be more than 2 inches in diameter, for a larger cylinder the com­bustion of the firedamp renders the top inconveniently hot’. The ‘Scotch Davy’, however, was made from 2.9 in. to 3.3 in. in diameter. Davy restricted the height of his gauze to 7 inches; in the ‘Scotch Davy’ the height was 10 inches, exclusive of cap or top.

The Romans mined for metals in every part of their empire. They sought both utilitarian metals such as iron, copper, tin, and lead, and the precious metals gold and silver. The desire for mineral resources may even have affected foreign policy. Before he invaded, Caesar knew of the rich tin deposits in Britain, a metal used in the production of bronze and in limited supply elsewhere in the empire [Caesar, 5.12].

Our knowledge of Roman mining comes from modern excavation reports of the mines and from literary sources, such as Diodorus of Sicily and Pliny. The written evidence does not discuss all aspects of mining, leaving out information such as how veins were located, what tools were used, or how drainage wheels were used to control water. When an author mentions a mine, it is rarely with enough information to identify an exact location. The mines themselves contain evidence for various processes, but we must interpret the remains. A number of Roman mines have been excavated and documented. Examples include the gold mine at Dolaucothi in Wales, and the extensive silver workings at Rio Tinto, Spain. Mining is a destructive process, so much evidence has been erased by Roman and later working. It is particularly difficult to date features such as shafts and tools. Some earlier mines, such as the Greek silver mine of Laurion, had a Roman period that may have had minimal effect on the mine features. The poor preservation of organic remains also limits the information. In Dolaucothi, for example, the investigators believe that only one board of a wooden drainage wheel survives in the mine because the other parts were burned in a fire set to loosen rock [Boon, p. 123].

Despite these limitations, it is possible to develop a picture of Roman mining. The Romans employed three techniques to recover the metals. Pliny describes them:

“Gold in our part of the world … is found in three ways: first, in river deposits. … No gold is more refined, for it is thoroughly polished by the very flow of the stream and by wear. The other methods are to mine it in excavated shafts or to look for it in the debris of undermined mountains.” [XXXIII 66; Humphrey, et al., hereafter SB, p. 187]

The least difficult was surface mining, where the ore was available at the surface either in streambeds or exposed on the ground. The erosive power of streams broke up the ore and the heavier metals settled to the bottom in areas of slower flow. These are called placer deposits. Where the Romans recognized metal ores on the surface, they could follow them into the ground by strip-mining the surface (“the debris of undermined mountains”), or digging short tunnels. This technique, called opencast, was used for many metals.

The third technique, deep-vein mining, was the most difficult and dangerous. Only gold and silver were valuable enough to justify digging underground. After a suitable site was found, tunnels were excavated in the rock to remove the ore. Narrow vertical shafts were driven through the rock, widening out to horizontal galleries where the ore was found. Sometimes horizontal adits from a hillside were driven as well. Working below ground, the miners had to deal with the need for lighting, the dangers of poor ventilation, and the presence of water in the tunnels. Figure 1 shows the structure of a hypothetical mine.

This report describes the characteristics of deep-vein mining, as well as the special problems involved. In addition to the writings of a number of Roman and Greek authors, the data come from archaeological excavation reports of Roman mines in Britain and Spain. This information is compared to practices described by Agricola in the 16th century, and activities at the colonial Reed gold mine near Stanfield, North Carolina.

The Romans lacked a theoretical knowledge of geology, but they (and the Greeks before them) made observations that helped them locate ore sources. Pliny [XXXIII 67 and 98] mentions the association of particular earths with ore. Sometimes they pursued the source of placer deposits upstream to the side valleys [Davies, p. 17]. They recognized the affinity of one type of metal for another [Pliny, XXXIII 95] and that metals often occurred where different layers came in contact [Davies, p. 17]. They made limited use of adits for prospecting [Diodorus, 5.36]. All of these methods helped the Romans locate possible deposits. The same techniques were used at Reed mine, where a placer find encouraged surface digging, and eventually the excavation of adits and shafts in the hill. Colonial prospectors relied on surface signs much like those the Romans observed.

The iron tools of the miner did not change into the colonial period. Agricola mentions using a gad like those found in Rio Tinto and Laurion [Forbes, p. 194], and the mine tour at Reed mine included a demonstration of how rock was removed with a gad and hammer.

Ore freed from the walls could be gathered into baskets or buckets with iron rakes, spades, or hoe-like mattocks [Davies, p. 33]. Baskets of esparto grass have been recovered from Spain [Davies, p. 30], and wooden trays were found at Rio Tinto [Craddock, p. 83]. From the Greek mine of Laurion (later lightly worked by the Romans) came a bronze bowl [Davies, p. 30]. Figure 3 is a 6th century BC Greek plaque showing miners using ore baskets and a pick [Shepherd, p. 35].

We have relatively few wooden or textile items surviving from Roman times. But in the mines, we occasionally find conditions in which these are preserved. Wood was used for buckets to remove ore [Davies, p. 30]. Several wooden ladders remain, as do wooden water-lifting devices (described later). The existence of wooden wedges is inferred from a large gallery at Linares in Spain that has no tool marks on it [Davies, p. 20]. These wedges would swell when wet, cracking the rock. Leather sacks, miners’ sandals and caps have also been recovered [Healy, p. 101].

At Palazuelos, Spain, an area where the Romans mined silver, was found a sculpted relief (Figure 4). It shows miners dressed in tunics with aprons of (presumably) leather to protect themselves [Rickard, JRS, p. 140]. The largest miner carries tongs in one hand, and an oil can or bell in the other. Another miner carries a type of pick, and another a lamp [Sanders, p. 321]. The depiction fits well with the mining equipment recovered from Roman mines.

With these tools, Roman miners dug vertical shafts and horizontal galleries and adits. The passages were small due to the difficulties of removing the rock. Diodorus describes mining,

“…opening shafts up in many places and digging deep into the earth, [they] search for the strata rich in silver and gold. They carry on not only for a great distance, but also to great depth, extending their diggings for many stades and driving on galleries branching and bending in various directions, bringing up from the depths the ore which provides them with gain.” [5.36-38; SB, p. 186]

Iron tools such as the pick or gad were used to make an initial groove, and then other tools (wedges, chisels, picks) broke away the exposed ridge [Davies, p. 20]. The Roman authors do not describe this process, but it is presumably similar to quarrying blocks of building stone. It was hard work: “those individuals of outstanding physical strength break up the quartz rock with iron hammers, applying to the work not skill, but force” [Diodorus, 3.12-13.1; SB, p. 184].

From the initial shaft, horizontal galleries could be driven at depth. The galleries followed the veins as they wove underground. The outline of the galleries was rectangular, with a height of only 1 - 1.5 meters and a width about 1 meter [Shepherd, p. 17]. There were some tunnels that were even smaller: “It is not possible for someone to stand upright while digging in the Samian deposits, but he must dig while on his back or side” [Theophrastus, On Stones 63; SB, p. 185]. Although he is referring to mining for clay, many galleries at Laurion were very cramped. Some galleries, such as at Rio Tinto and Dolaucothi, were slightly larger near the roof, perhaps to accommodate the men’s shoulders or ore baskets borne at shoulder level [Rickard, JRS, p. 132; Manning, p. 301]. Rarely galleries were quite long, such as the 2.2 km ones Pliny ascribed to Hannibal [XXXIII 96].

The galleries were supported by wood bracing, called ‘propping’ ["The earth is held up with wooden supports", Pliny XXXIII 68; SB, p. 187] or by pillars of unmined rock. The rock pillars were critical, and there was a penalty of death if these were mined [Plutarch, 843d]. The danger of roof collapse was always present, as evidenced by the crushed skeletons found in Asia Minor and a passage by Statius describing a miner crushed under the rock [6.880-885]. In the lex Vipasca (a contract for the lease of the imperial mines, second century AD), wood propping was obligatory [Bruns, p 293-5; SB, p. 180.]

The deep mine workings created problems with ventilation, lighting, and drainage. The Romans knew the dangers of bad air in the mines. Pliny writes, “The fumes from silver mines are harmful to all animals” [XXXIII 98; SB, p. 175], and “when well shafts have been sunk deep, fumes of sulfur or alum rush up to meet the diggers and kill them” [XXXI 49; SB, p. 190]. Similar passages occur in Lucretius [6.808-815], Strabo [12.3.40], and Vitruvius [8.6.12]. The latter author mentions lowering a lamp into a (well) shaft to determine if the air is dangerous.

In addition to bad air, the mines were hot. For every 30 meters deeper, the temperature increased 1 degree Centigrade [Healy, p. 82]. The depiction of Greek miners (Figure 3) working naked shows that heat was a common problem. The use of fire-setting (described above) to drive galleries could only have added to the ventilation problems.

The miners often spent long periods in the dark, with only oil lamps for lighting. Pliny says that the lamps measured the periods of work [XXXIII 70], perhaps a daily shift of 8 or 10 hours. The miners used oil lamps like those found in Roman homes. These were stone or terracotta dishes with a wick [Figure 5]. The lamps were found in niches in the walls [Forbes, p. 210]. Diodorus [3.12.6] mentions lamps mounted on the miners’ heads, but there is no other evidence of this. At Reed mine, the candles were worn on the heads of the miners. Mounting the lamps would bring the light where the miner needed it. Torches could have been used for light as well, but they would have added to the ventilation problems.

Vitruvius mentions that men tread on the water-wheels to turn them [10.4.2], but gives no specifics. Wear patterns on the cleats confirm that some wheels were turned this way (Figure 7). Some cleats project from the side of the rim, parallel to the axle. These wheels could be turned by hand or pushed by men’s feet. One wheel in Tharsis (Spain) had bits of rope surviving, suggesting it could be pulled by hand [Shepherd, p. 37-8].

       
    Photo by Tina March                       Photo by Tina March

Demetrios died sometime between 30 B.C. and 395 A.D.  and is currently on display at the Brooklyn Museum.  What do the petrified remains of a fifty-something year old have to do with our event?   Demetrios’ linens are coated in red paint containing lead from the Rio Tinto mines. 

    Photo by Tina March

To learn more about Demetrios, check out the Brooklyn Museum’s blog site at:

http://www.brooklynmuseum.org/community/blogosphere/bloggers/author/marcht