A Curated Object - An Unremarkable Cup
One of my favourite possessions is a basic utilitarian object: a sixty year-old glazed stoneware rubber tapping cup. When Dad gave it to me a few years ago, I was delighted. Others might see it best used as drainage in plant pots. But to me it is a remarkable object: aesthetically pleasing, a reminder of my childhood, and an object that speaks resoundingly of colonial power and the rise and fall of a lucrative industry that changed an entire country. So much significance for such a modest object!
Dad acquired the cup in Singapore where he was posted by the RAF from 1959 to 1962 to develop aerial reconnaissance photographs towards the end of the Communist insurgency of 1948 to 1961. This was the happiest time in my parents’ marriage. A third daughter and a son were added to our existing family of four, and we enjoyed all that RAF life offered. As often as he could, Dad would take us into the countryside to see wildlife and the local people going about their lives. Family photographs record at least two trips to rubber plantations.
Balancing the cup in my hand, I am always surprised at its weight - over 10 ounces, or 289 gm. It is cold. The greenish-grey glaze covers three-quarters of the outer surface, and is extensively crazed with tiny cracks which are most obvious around the rim where the glaze is at its most glassy. A single long crack runs through the cup from the rim almost to the base. At least an inch from the base, and on the base, it is unglazed. That surface is pitted and marked with the brown impurities in the stoneware clay from which the cup was fashioned, by wood ash from the firing, and by a few chips, kiln rest marks, and the handling marks of the potter. Inside the cup, for half its depth, the glaze is stained earth-brown with what, in part, may be dried latex.
Latex begins life in plants, and is a whitish or yellowish milky fluid containing proteins, starch and alkaloids. Some latex also contains rubber, a polymer which is a chemical compound with large molecules made of many smaller molecules of the same kind. Around 20,000 species of plants produce latex, but only 2,500 species have been found to contain rubber in their latex. Its biological function is thought to be aiding healing from damage, and blocking the entry of harmful bacteria and viruses.
My modest tapping cup had a single purpose: to collect latex
from Hevea brasiliensis trees in a Singapore plantation. These tall
deciduous trees, members of the spurge family Euphorbiaceae, are
native to the Brazilian Amazon. They require a tropical or subtropical climate
with a minimum of about 1,200 mm per year of rainfall, and no frost. In
the wild, they can live for a century and grow to 43 m (141 ft.), but
cultivated trees are stunted by the process of latex collection and have a maximum
lifespan of thirty years as their latex production declines.
Mesoamerican peoples in Mexico and Central America were using liquid rubber some 3,600 years ago for medicines, in rituals and games, and to paint. But it was only with the journeys of Italian explorer Christopher Columbus (1451-1506) in the early 1490s that knowledge of rubber spread to the western world. In 1615, Friar Juan de Torquemada, Spanish missionary and historian (c.1562-1624), wrote about indigenous and Spanish settlers of South America strengthening and waterproofing footwear, clothing and hats by dipping them in latex. In 1734, the French explorer Charles Marie de la Condamine (1701-1774) discovered the Hevea brasiliensis and Castilla elastic trees. The former has a unique system of connected latex tubes, meaning it can be made to bleed latex from man-made incisions in its bark. The commercial collection of latex was now a possibility, but it took until Charles Goodyear’s invention of vulcanisation (treating rubber with heat and sulphur) in 1839 to overcome rubber’s inherent disadvantages of hardening and cracking in cold weather and becoming sticky in warm weather. In 1888, Dunlop invented the air-filled rubber tyre and rubber became an essential raw material that helped to fuel the Industrial Revolution.
Unsurprisingly, where there is a valuable natural asset there are also political, economic, social and environmental implications. The Amazon was the only source of Hevea brasiliensis, and the Brazilians were able to control both prices and the export of rubber seeds and seedlings. However, this domination was ended by Sir Henry Alexander Wickham (1846-1928). His Wikipedia entry describes him as “a British explorer and plant-thief”. The popular story is that, working for the British government and posing as a plant collector, Wickham spent a year collecting rubber seeds from commercial rubber groves in Brazil. In 1876 he successfully smuggled 70,000 rubber seeds, hidden in banana leaves, to England. Those seeds produced just 1,900 seedlings, which were sent to Ceylon (now Sri Lanka), Singapore, and Malaysia to start the first rubber plantations in Asia.
Other sources dispute that Wickham stole the seeds, in fact having the permission and goodwill of the Brazilian government. I find that improbable, given that the Brazilians were enjoying all the economic benefits of a monopoly. Whatever the truth, just 12 years after the Ceylon plantations were established, their rubber production was on a par with that in the Amazon, and by the start of World War I had outstripped it to become the world’s primary source of natural rubber. The Amazonian trees, afflicted by the indigenous South American leaf blight and grown haphazardly in their natural environment, had no chance to regain their crown. Within a few decades, the British had established control of the world rubber market.
The first Hevea brasiliensis planted in Singapore were re-discovered in 1888 by the English botanist Henry Nicolas Ridley (1855-1956) at the Botanic Gardens where they had been for a decade. He was such a passionate advocate of the potential for rubber-growing in Singapore that he earned himself the nickname "Mad Ridley''. Gradually, he was able to promote rubber to the extent that it challenged the economic dominance of tapioca, pepper, sugar and coffee. He also, after extensive experimentation over a five year period, developed a revolutionary method for increasing the latex yield, and the reduction of tree disease and death. His invention was continuous tapping of the trees in a herring-bone pattern with bark removal. Previous tapping methods cut through the bark without removing it, making cutting depth hard to judge.
The photograph accompanying this article, taken in 1961, is of me inspecting a rubber tapping pot (not the one I now possess) in a Singapore plantation. The scars of repeated incisions in the tree bark are clearly visible on the other side of the trunk in what is called the “tapping panel.
I do not know where Dad found, was given, or bought, the tapping cup. Along with millions of others like it, it would have started life at one of the 20 or more “Long Yao” (dragon kilns) built in Singapore. The dragon kiln technology, which dates back at least 2,000 years in China, was brought to Singapore by migrant workers in the early 1900s. These long, tubular wood-fired kilns were named because they resembled the mythical dragon with a “head” (the firebox) at the bottom of a slope or hill and a smoking “tail” at the top. They were partially covered with bricks, resembling the scales of dragons, and varied in length from 30 to 100 metres, and were about 2.5 metres high and wide.
I have been unable to identify all the dragon kiln locations in Singapore, as only two now remain (and only one is operational) but there is one candidate which could be the birthplace of my cup. This is the Sam Mui Kuang dragon kiln once located at 101 Jalan Hwi Yoh, which was within easy reach of the Seletar air base where Dad was stationed. On a 4,500 square metre site, the 50-metre long kiln undulated up a hill. It fired about 9,000 pottery items monthly, in three cycles each lasting about a week. Sadly, the site was bulldozed for industrial and housing development in the 1990s.
The kiln site would have been surrounded by jungle, and the workers would have lived in a nearby kampong (rural village) in timber houses with thatched roofs made from attap leaves. Vast numbers of workers would have been employed in back-breaking work, as described in a Singapore Free Press article of 24 September 1949 by Marian Wells[1]. She had visited a modest-sized brick kiln of “sixty feet long” (c.18m) which “on the far end, at the downward slope” had “a fireplace strewn with ashes” from the previous day’s firing. She describes the clay excavation: “men and women were unearthing lumps from ten to fifteen-feet deep holes and carrying their loads to long atap [sic] sheds”. She reports how the workers removed stones and foreign particles, and used their feet to pound the clay (to remove air bubbles that could cause explosions in the kiln), before drying, moulding, carrying, packing and firing the objects. In a 1989 interview, one of the owners of the Sam Mui Kwang dragon kiln, Mr Chua Soo Kim, stated that it would take about two days to prepare 60 tons of clay by hand. This hard labour continued into the 1970s when the process of kneading, stirring and watering the clay was mechanised.
I have not been able to discover the nature of the glaze used on the cups, but it was an essential part of the process, sealing and strengthening the porous clay. All glazes are made from three different elements: glass-forming substances (e.g. silicon dioxide/silica from quartz, flint and other metal oxides); a refractory or stiffening component to prevent the glaze slipping (e.g. aluminium oxide/alumina from clay, cryolite and feldspars), and a flux (e.g. bone ash).
The intense physical effort required to complete the pottery would continue until the end of firing. In the “belly” of the kiln, the kiln house, there were chambers where thousands of tapping cups and other utilitarian objects such as water jars, crockery, bricks, roof tiles, and pipes, would be stacked on top of each other or packed neatly on racks. They would be separated by clay balls or cockle shells to prevent them from fusing to the shelves and to ensure a smooth flow of heat and fire through the kiln. If required, items that could withstand the greatest heat were placed near the "mouth" where the temperature could reach 1,300°C (compared to 1,000°C at the “tail”). Timber pieces, usually from rubber trees, would have been slotted into the sides of the inner chambers. Then the access openings to the kiln chamber would be sealed with bricks and a mixture of sand and clay.
Prior to the start of firing, prayers and ritual offerings of fruit and money would have been made to the kiln god in its altar above the firing box. To prepare the kiln and its contents for full firing it would be thoroughly dried for 12 to 20 hours by lighting a fire in the firebox and gradually increasing the temperature. If the kiln heat was too excessive at the start of the firing, moisture would be drawn too rapidly from the clay and the pottery could explode. Once the temperature in the firebox reached 1,260°C it would be sealed.
For each firing, between five and 10 tonnes of wood would be required over a period of three or four days. Throughout, workers would monitor the temperature of the kiln by observing the colour of the flames (at their hottest, they burned white), and continue feeding in wood via stoke holes or “eyes” along the body so that each chamber was fired in turn. If the fire temperature dropped too low, the entire kiln contents would be ruined. It must have been a remarkable sight, like a scene from Dante’s Inferno, with workers feeding the insatiable beast day and night. In addition to the escaping smoke at the tail end, when fully fired the kiln would become even more dragon-like by emitting roaring and hissing sounds.
Inside the kiln, the pottery would have been encircled in flames and coated in falling fly ash and volatile salts. The interaction between flames, ash, minerals in the clay, and the glaze would form unique colours and textures on every item. With firing finished, the kiln would be left to cool for up to a week before being emptied. Only then could the thousands of newly-minted tapping cups begin their useful lives on the rubber plantations.
I have found several accounts of the poor labour conditions of the rubber tappers in Singapore, whether Indian, Chinese, or Malay. They would have been housed in the plantations, with few amenities, and the work would have been relentless. Starting very early in the morning in darkness (as the sun stops the flow of latex) and using oil lamps, the tappers (often women), would remove the tree bark in the approved V-fashion. The latex would flow from these to a centre vertical slit that ended at a metal guide which drained into the collection cup. If the tapper was careless, they could damage the tree and the profitability of the plantation. They also faced physical dangers, such as communist insurgents, deadly snakes, tigers, and mosquitoes that could spread what we now know to be Zika Virus, Dengue Virus, Chikungunya, Crimean-Congo haemorrhagic fever, and leishmaniasis.
The tappers would have been on what we now call zero hour contracts. They were paid according to the amount of latex their tapping produced, and they could not work in rain. Malaysia became rich on the back of its rubber industry, but the workers who possessed highly specialised skills had no share of the wealth they created and were denigrated as unskilled.
Singapore’s dragon kilns thrived in the early part of the 20th century, many of them fired every fortnight and turning out hundreds of thousands of pieces every year. But the industry was not to last. Rubber industries were booming or establishing elsewhere in Asia, India and Africa, and in Singapore the plantations were allowed to dwindle. With them fell demand for clay tapping cups from the dragon kilns, many of which fell into perpetual slumber.
In the final coup de grâce, new technologies automated pottery production in huge factories; advanced new kilns ran on oil, gas, or electricity, with greater efficiency; and sensors and pyrometric cones revolutionised temperature control. Although the dragon kilns diversified into producing pots for domestic purposes, and beautiful decorative pieces, by the 1980s only three remained: Sam Mui Kwang, Guan Huat, and Thow Kwang. Now only Thow Kwang at Jalan Tawas off Jalan Bahar in the west of the island, established in 1940, is still in operation. It is run as a tourist attraction and creative arts hub and is surrounded by vast CleanTech Parks.
Millions of tapping cups would have been discarded over decades, gradually returning to the earth from which they were formed. Now, wood-fired pottery is one of the elements listed in Singapore's Intangible Cultural Heritage inventory, launched in 2018. Humble rubber tapping pots are now displayed in museums, helping to enlighten Singaporeans about their heritage.
I am proud to possess such a simple, but historically and culturally significant object. It sits on my study bookcase, to be picked up occasionally and studied, admired and appreciated - which is nothing less than it deserves
The latex it held may have been used in any one of thousands of products, from waterproofs to insulation, toys to tyres. The mass production of these cups led directly, in their own decline, to diversified pottery production in Singapore. It speaks of the history of one of the world’s most valuable raw materials which, for half a century, was the mainstay of the Malayan economy. It reminds me, too, of the triumphs of early global exploration; of the rise and fall of empires; of the achievements of science and human invention; of human interference in natural landscapes; of the exploitation wrought by colonialism; and the need for social justice and human rights
It also reminds me of my earliest conscious childhood years
in a fascinating country to which I hope to return. I want to visit Thow Kwang on
one of the firing days it holds just three or four times a year. I would give
much to see and hear a dragon breathe.
Barbara Grafton
Image copyright Barbara Grafton.
Sources & further reading:
https://www.anagrams.net/generator/Rubber%20tapping
https://en.wikipedia.org/wiki/Hevea_brasiliensis
https://eresources.nlb.gov.sg/history/events/a8ceea4c-1c8b-4c9a-885c-b85038b39e4
https://historyofrubber.weebly.com/rubber-production.html
https://jbcssg.com/history/guan-huat-dragon-kiln/
https://julianalim.wordpress.com/2012/03/15/death-of-a-dragon-kiln/
https://ktemoc.blogspot.com/2006/06/malaysias-economic-backbone.html
https://ktemockongsamkok.blogspot.com/2007/08/my-unforgettable-rubber-tapping.html
https://www.lightfoottravel.com/en/travelbylightfoot/singapores-oldest-dragon-kiln-revealed
https://thelongnwindingroad.wordpress.com/2012/12/03/a-dragon-draws-breath/
https://thelongnwindingroad.wordpress.com/2011/06/29/into-the-belly-of-the-dragon/
https://thelongnwindingroad.wordpress.com/2015/06/22/keeping-the-fire-burning/
https://thelongnwindingroad.wordpress.com/?s=rubber+tapping
https://medium.com/kampung-seaport/the-last-dragons-in-singapore-12ade3f04b3c
https://mothership.sg/2017/12/dragon-kiln-singapore/
https://thepotterywheel.com/what-is-pottery-glaze-made-of/
https://remembersingapore.org/jalan-bahar-dragon-kiln/
https://www.roots.gov.sg/learn/stories/the-dragon-kiln-breathes-thow-kwang-dragon-kiln/story
https://www.tnp.sg/news/firing-last-singapores-dragon-kilns
https://www.unesco-ichcap.org/singapores-first-inventory-for-intangible-cultural-heritage/
https://www.wisearchive.co.uk/story/how-and-why-i-became-a-rubber-planter/
What a wonderful, evocative and informative article - thankyou!
ReplyDeleteAs a student of prehistoric and Roman kiln firing techniques, I very much enjoyed reading about the dragon kilns.
How rich in meaning the simplest object can be!
Many thanks, Paul. I contacted the Dragon Kiln at Thow Kwang about the glaze constituents but unfortunately they did not reply.
ReplyDeleteWe accumulate so many objects throughout our lives, but very few hold any meaning at all when we think about them; this rubber cup speaks volumes, though!
When we are finally able to meet up it will be my pleasure to show it to you.