The key material in the physics most familiar to all, the material most critical to modern life, is rubber. The expression "rubber meeting the road" is our shorthand for getting down to any task of real work, even if we don't think about the actual physics of rubber and roads till tires skid.  Crude or tree rubber for pneumatic tires made possible the automotive era and life today.   Over a century of unparalleled improvements in human living conditions were built on crude rubber, which continues to provide essential transportation and other vital elements.

     Akron, Ohio and crude rubber have a long history. Akron's rubber companies held 520 square miles of rubber tree plantations, equal to nearly two-thirds of the watershed of Ohio's 85-mile long Cuyahoga River. Plantation rubber made Akron, more than any of the many industries started here and exported.  Four large rubber companies and a host of smaller ones were founded in Akron, with tens of thousands of employees. In its glory days, when Akron was Rubber City, the smell of rubber denoted jobs, money, homes, polymers at Akron U., mansions, and also the black soot on clothes hung to dry.


     Natural rubbers are produced from latex, which is found in the outer layer of many thousands of plants. Latex makes these plants unpalatable or deadly to herbivorous animals and boring insects and "bandages" damage to the plant.  In fact, it is collected by intentionally damaging the plant.

     Of plants with rubber latex, only the Hevea Brasiliensis tree is significant. Its rubber has the high tensile strength, long usage life, good wear, adhesion, and traction essential for radial and aircraft tires and many other critical applications, many of them related to rubber's having the unusual and highly desirable property of shrinking when heated. Hevea has special needs: abundant sunshine and rain, high humidity, good soil, and good drainage. Seeds grow in pods, which explode with a pop, throwing them well beyond the canopy of the tree. High winds and leaf blight are deadly, and a cold snap minimizes production permanently.

     Hevea rubber trees provide a small amount of latex per tapping, which is done every other day and requires two visits.  To improve yields, bud grafting was developed by the Dutch in 1916.  Yields rose to 10-15 pounds per year per tree, improving the tree's defense mechanism without increasing labor cost.  Today's annual yields are approximately 20 pounds per year per tree (two ounces per tapping), and genetic manipulation holds promise of achieving 30.
 
     The work required to gather rubber makes tires the most labor-intensive parts of vehicles, seeing as a rubber plantation requires some 80 workers per square mile.  Tappers start at first light since trees "flow" only in the morning.  At each tree, they collect the dribble "cup rubber" and "lace rubber" in the previous cut for lower requirements.  They then tap halfway around the tree, removing a thin slice just below the previous cut, and move on to the next tree.  Returning after a late breakfast, they collect the latex and take it to collection barrels, adding ammonia to prevent coagulation. 

     Barrels are emptied into factory basins with opposing dividers placed so that the rubber will coagulate into a thick blanket.  This is fed through a series of mills, which squeeze out the water, reducing the thickness, and then imprint ribbing.  Strips are cut and hung on bamboo poles which are placed on rail carts that are rolled into a smoke house for curing before being bailed as "smoked rib sheet."  For higher grade "pale crepe," mills are rough, and long strips are hung to air-dry.  Some plantations now use dewatering systems and ship concentrated latex in large tanks.

     Extracting latex stunts growth, so approximately 100 cultivated trees can be planted to the acre. with about 6-meter spacing to allow for the mature tree's spread of leaves.  After 30-40 years, yields decline, and if the planting of higher-yield clones after a seven-year gap makes sense, trees are cut down and replaced.  Today the wood, which used to be burned to make way for new trees, is valuable, particularly for wooden toys.


     Although rubber was used for waterproofing in the Americas long before Europeans arrived, and to make balls for ancient Mayan games, up until about 1820 the industrialized world had little use for rubber, which was available only in the wild.  But demand for rubber for waterproofing grew rapidly (think of the demand for waterproof Wellington boots in rainy England), especially after Charles Goodyear developed vulcanization in 1839.  The automotive revolution created an eruption in demand. 

    Initially, the automotive age and the forces organized for the gathering of wild rubber spurred a tragic era of atrocities, slavery, and millions of deaths. Vicki Baum's The Weeping Wood (about the Amazon) and Joseph Conrad's Heart of Darkness (set in Africa) describe these horrors.  In the Belgian Congo under King Leopold, rubber came from the white rubber vine, Landolphia Owariensis.  Leopold and Belgium became wealthy on African rubber, and Amazon exploitation paid for modernizing the "rubber" cities of Belem and Manaos, Brazil, at the mouth of the river.  Mansions and luxurious opera houses were built, which brought top stars from Europe and the US.  The horror ended only when lower cost plantation rubber captured the market.

     Rubber plantations got their start when Henry Wickham left Brazil with 70,000 hevea seeds, which he took to Kew Gardens in 1876. Due to the seed's short shelf life, only 2,500 germinated. Unfortunately, Kew refused to let him have anything to do with them, despite his knowing more about rubber growing than anyone in England, and hevea domestication was delayed for two decades while people suffered and died. 

     Finally, in 1896, hevea was planted in the English colonies Malaya and Ceylon, where conditions were suitable.  By 1900 there were 10,000 plantation trees, growing to 2.5 million in 1914.  By 1916, the once-booming South American rubber cities were devastated.  Today, billions of trees yield over 13 million tons annually and supply 40% of the rubber market.  From wild to cultivated millions of trees in two decades, to billions—all from a few seeds collected in 1876!

     Plantation rubber brought new residents to Asia, such as my parents, and attracted visiting celebrities. On one occasion in 1928, Will Rogers joined my parents for breakfast before they crossed the Malacca Straits to attend a reception where they met violinist Jascha Heifetz on their way to Goodyear's new Sumatra Wingfoot Plantation.


     While demand grew steadily from 1820 to 1910, it exploded in the auto age, with a fourfold increase in the next decade.  Uneven growth in demand for automotive tires led to boom-and-bust market conditions, as it did for oil.

     Great Britain's outstanding public figure of last century, Winston S. Churchill, attempted a one-country rubber OPEC, so to speak, when rubber prices fell soon after World War I, leading to one of the great statesman's rare failures. As Secretary of State for the Colonies, Sir Winston appointed a commission, led by Sir James Stevenson, to find ways to stabilize rubber prices in Britain's favor. The resulting 1922 Stevenson Act limited exports by setting higher tariffs on larger exports.  The price of rubber reached almost $20 per pound in today's dollars, dramatically higher than the current price of 80 cents, igniting competition that devastated Britain's dominant rubber position. The Stevenson Act led Commerce Secretary, later President, Herbert Hoover and Congress members to urge rubber companies and Ford to get into rubber plantations.   

     Goodyear had already purchased the first Akron-connected rubber land in 1917, a 32 square mile plot in Dutch Sumatra called by its native name, Dolok Meranger, meaning "the place where Batik ladies wash their hair."  After clearing and planting, seven years' maturation had to occur before useful production could begin.  The next American plantations began in 1926, with Goodyear and Firestone the US leaders. Elsewhere in the US, an East Coast shoe trust, later Uniroyal, dabbled in plantations from 1911 and later held 50 square miles.  In 1927, Ford began investing massively, ignorantly, and futilely in Brazil (a tragicomic story told in Greg Grandin's book Fordlandia).

     Goodyear developed two more Sumatra plantations, the 64-square-mile Wingfoot, which my father helped to start to develop under a Dutch manager, and later the 52-square-mile Lepan. Interestingly, even with Kew's delay, this completed the trip of Wickham's seeds around the world in 60 years, while trees from his seeds were still living.  One plantation was just 84 miles from where Wickham left with his seeds. The returning trees were impressively more productive.

     A remote, tiny four-square-mile plantation called Pathfinder in the southern Philippines, out of the typhoon belt, is where I grew up. It was reached by sailing 80 miles along the Sulu Sea from Zamboanga, then 13 miles up a winding river through the jungle.  Pathfinder was a "nursery" to develop and produce high-yield, hardy bud-grafted seedlings for Goodyear's Central and South American plantations.  Its first rubber was produced in 1934, and when we arrived in January 1935, its first shipment of seedlings went out. To achieve better yielding seedlings, production was monitored and test plantings made.  Goodyear's Director of Plant Research, Dr. Walter Bangham, and an assistant spent weeks living in our huge house while working with my father to develop improved clones.  Weekends the Doctor would search the jungle for previously unknown plants, occasionally returning triumphantly with damp, newspaper-wrapped bundles.

     In a unique arrangement, Goodyear supplied high-yield bud-grafted seedlings and support to some 700 small independent growers as the threat of war made critical the need for non-Asian rubber.  Goodyear had a total of 92 square miles in four small plantations and secure purchase agreements in the Americas. 

     After World War II, B. F. Goodrich acquired the 28 square-mile Guthrie Plantation in Liberia, where Firestone had already invested heavily, leasing 15,000 square miles and building the largest Akron-held rubber plantation at 251 square miles.  A friend was the last Akron manager of this plantation.  Following Charles Taylor's revolution (1989-96), my friend finally found a way for his family to leave and later extracted himself. 

     Goodyear and Firestone had more workers on their plantations than in their Akron tire factories.  Akronites, including my own family for a span of twenty-one years, went to remote parts of the world with their families to run these tree farms totaling tens of millions of trees.  And behind it all, surprisingly, was Winston Churchill.


     Rubber became extremely critical as Japan invaded Manchuria in 1931, then China in 1937, and war loomed, putting Asian plantations at risk.  Goodyear Sumatra production accelerated to three million trees being tapped in 1941, but the US had only a 20-month peacetime supply on hand.  The war was expected to last 10 years, paced by the availability of rubber, arguably America's most critical war material.  Firestone's Liberia plantation provided less than a quarter of the prewar need.
 
     Seedlings were so critical they were being shipped back from the Philippines on B-18 Bolo bombers (about to be phased out of combat service), the last just eleven days before Pearl Harbor.  But just as the first 1935 Pathfinder shipment would not reach reasonable production till 1942, the seedlings on the last B-18 shipment would not mature until 1948.

     War came too soon, and the need was vital. Each Sherman tank required half a ton, and battleships had 30,000 rubber parts.  To preserve rubber, gasoline was severely rationed to reduce driving, speed limits lowered to reduce tire wear, and tires retreaded.  Reclaimed rubber, which grew to provide a third of that used in the Stevenson Act period, went into high gear.  Non-hevea rubber filled many needs. 

     Rubber companies joined forces for synthetic development and rubber acquisition.  Beside the well-known story of synthetic rubber, which, after massive investments, reached almost a million tons a year of lower performance rubber, there was a tremendous drive to find any kind of rubber closer at hand than the South Pacific. 

     Some 50 square miles in the Southwest were planted with the latex bush Guayule, the only appreciable rubber producer in the US.  Thanks to recent developments, it now took three rather than twenty years to grow.  Bushes were pulled out and processed for their 20% of latex and new plants started.
 
     Men from Akron went back to the South American jungle to restart wild rubber collecting, but without exploitation.  A Goodyear man introduced a system that kept tappers and intermediaries reasonably paid and incentivized.  The castilloa tree was tapped twice a year, by climbing the tree.  The sum of these efforts produced 440 tons the first year, growing significantly thereafter.  Without synthetics, desperate natural rubber efforts, rigorous conservation and reclaiming, World War II may well have lasted ten years. But the US was essentially rubber broke at the end of the war. 

     When the Philippine plantation was reached by the US Army in 1945, they found that during the war the staff had laboriously produced and hidden 33 tons of rubber from Japanese patrols—so notable a feat it was noted in a May 1945 Life magazine.


     In the Philippines, Goodyear managers returned immediately after Japan's surrender to rebuild, but Goodyear's Sumatra plantations needed considerable work. For instance, piping had been used by the Philippine-American guerrillas to make shotguns. To complicate matters, Sumatra was a hotbed of revolutionary activities, and Goodyear couldn't get to one plantation until 1949.  Nonetheless, the postwar return to normal domestic consumption created a tremendous demand, so resuming production was crucial. Goodyear soon had 50 of its own people on the plantation, with Firestone and Goodrich making a similar effort on their two plantations. 

     While Akron's rubber plantation holdings peaked in the decades after WWII, today there are none.  So many rubber-producing trees were planted around the world to the point that Akron's trees constituted less than 1%.  The world's rubber plantations combined cover an area larger than the state of Ohio and employ several million.  Rubber became a commodity with a wide production base, and several factors (nationalization, increase of qualified suppliers, cost, and revolutions) made moot the logic of rubber plantations ownership for Goodrich, who sold in the 1980s, and Goodyear, who finally sold their Sumatra plantations in 2005.

     When Firestone was acquired by Bridgestone, the Liberian plantation became their headache to deal with in the face of revolution, poor labor productivity, and environmentalist groups objecting to the jungle being used for rubber.  There is an irony in these objections, since for over 12,000 years people have repurposed land to provide enough food, clothing, shelter and transportation.  Further, rubber plantations are dense, manmade forests, their ground-holding cover-crop amounting to another green layer.   The development of higher-yielding trees is already reducing the planted acreage, which is being repurposed, not returned to jungle. 

     When the company called me about managing the Philippine plantation in the mid-1960s, I declined. Though my wife Julia was willing to live on a remote plantation, manage a household staff of five or more, and homeschool our children, as my mother had done, I recalled Dad had said there was no future in crude rubber. Although Akron's plantation era has ended, it was an exciting time that brought an international flavor to Akron, like the Rubber Room with its rubber walls at the Portage Hotel.  It is gratifying to have known Goodyear's CEO in this era, Goodyear's botanist and the man who surveyed Sumatra, bought the first plantation and first ran Goodyear's Crude Rubber division.  Others include my father who helped start Goodyear's largest plantation and ran the seedling/development plantation, the man who led WWII wild rubber efforts, the last Akron Liberian manager, the first Filipino manager of the Philippine plantation and many others of the 'Old Crude Rubber Crowd'.
    

     Besides the two books mentioned, material comes from studying the rubber plantation growing up, discussions over the years with crude rubber people and my father's 1935 letters concerning the plantation. I was also fortunate to have access to six boxes of Goodyear plantation files in the University of Akron Archives.

Allen, Hugh. House of Goodyear. Corday and Gross, 1949.

---.  Goodyear Rubber Plantation (pamphlet) No publisher (but probably Goodyear) and no date. A copy found in a U. of Akron Archive's Goodyear plantation box.

Figart, David M. The Plantation Rubber Industry in the Middle East. Report to Secretary of Commerce Herbert Hoover per authorization of the 67th Congress.  Government Printing Office, Washington 1925.

Huber, Thelma. Such a Life. Joseph C. Huber, Jr., ed.  AuthorHouse, 2014.

Klippert, W.F. (Moe).  Reflections of a Rubber Planter. Vantage Press,1972.

Lawrence, James Cooper. The World's Struggle with Rubber. Harper and Brothers, 1931.

Naunton, W.J.S. What Every Engineer Should Know about Rubber. 1954.
London and Tonbridge, England: Brown Knight & Truscott, 1959.

Wolf, Howard & Ralph. Rubber. Covici-Friede, 1936.






     Joe Huber grew up on a remote Goodyear Plantation (Pathfinder Estate) his father managed.in the southern Philippines, roaming barefoot with his siblings in the surrounding jungle.  He has maintained contact with rubber plantation people (called the Crude Rubber Crowd) ever since, though sadly most have passed away.

     After surviving the Battle of Manila and Japanese prison camps, he went on to receive SBEE and SMEE degrees from MIT, specializing in engineering electromagnetic waves. 

     Joining Goodyear Aircraft, now Lockheed Martin, he had the pleasure of creating dozens of designs for the Cold War and received a number of patents in a 50-year career. 

     He continues active in church, Rotary, and other organizations with his wonderful wife Julia and their family.  COVID-19 has given him the time to complete his second book.

     He serves as Secretary of the Akron Club, where he presented this paper was presented on October 28, 2019.

     He can be reached at jhuberjr@neo.rr.com.