As is apparent from the Grantville maps, rubber can also be grown in south India, Ceylon, Burma, Cambodia, south Vietnam, and the Philippines. The Dutch and Portuguese have major settlements in India and Ceylon, as the Spanish do in the Philippines. The other areas are more open to infiltration by USE.
It is important to note that the Dutch are, at least for the time being, the dominant naval power in both the Indian Ocean and the southeast Asian waters. Before the RoF, the Dutch were in the process of taking control of the spice trade away from the Portuguese, and were ruthless in their treatment of trade rivals. However, since the Dutch are not going to be receiving reinforcements from home any time soon, they are likely to be on the defensive, and low in morale. The second European power of the region, the Portuguese, is likely to reassert itself. Moreover, the English may come back in force, looking for revenge for the 1623 Dutch massacre of the English at Amboina, as well as for profit.
If the USE tries to establish rubber plantations in the Indian subcontinent or in southeast Asia, its agents will need to build fortifications and make alliances, lest they be eliminated (like the English in Amboina in 1623, or the Portuguese in Malacca in 1641). To me, the best bets are in Thailand, in the southern Malayan state of Johore, in the Mataram kingdom of Java, and in north Borneo, where other Europeans are either relatively weak, or balanced by a strong indigenous power.
Africa
In Africa, the indigenous rubber trees (Funtumia elastica) are said to be in central Africa, from "Uganda to Sierra Leone" (EB11). You can get a better idea of where to look by consulting the vegetation map in the Hammond Citation World Atlas (I feel it safe to assume that someone in Grantville owns a copy.) This shows that there is tropical rainforest in modern-day Senegal, Guinea, Sierra Leone, Liberia, Ivory Coast, Nigeria, Cameroon, Gabon, Congo and Zaire, and light tropical forest in those countries as well as in Uganda. There are also economic maps in that atlas, and they show that rubber is presently grown in Liberia, Nigeria, and the middle reaches of the Congo.
EB11 also reveals that it is possible to cultivate, not only Funtumia elastica, but also the Latin American rubber trees, in Africa. The Para and Castilla rubber trees thrive under pretty much the same conditions as Funtumia, while the Ceara tree is better suited for drier conditions (compare the Hammond Citation Atlas vegetation maps for Brazil and Africa).
If the February, 1948, issue of National Geographic can be found in someone's attic or basement, it will reveal the location of the Firestone Para Rubber plantation in Liberia as being mostly within the triangle formed by the modern towns of Careysburg, Kakala and Harbel.
In West Africa, the Europeans don't control large territories. However, they do have forts and trading posts. The principal Portuguese forts are at Elmina, Axim and Chama in Ghana, Sao Salvador, Sao Felipe and Sao Jose in the Congo and Luanda/Sao Paulo in Angola. The Dutch are based in Mouri (Ghana) and the fort of Sao Tome (near Guinea). This would be well-known to the major down-time merchants. My inclination is that if the USE tries to develop a rubber trade in Africa, it will look to Liberia and Nigeria first.
What might be the effect of the rubber industry on the slave trade? It is very likely that if the down-time Europeans outside USE control awake to the advantages of rubber, that they will use African slaves to collect it in the New World. If USE citizens employ foreign factors there, they may unwittingly contribute to this tragedy.
On the other hand, a West African-based rubber industry might serve as a brake on the slave trade, by giving the local chiefs an incentive to keep the available labor force home to grow rubber rather than send it abroad. Besides attempting to grow rubber, we could also have African partners cultivate cocoa, coffee, oil palms, and so forth, and perhaps we could even drill for oil in Nigeria (see Drillers in Doublets).
* * *
Transplanting rubber seeds from one part of the world to another was much practiced in OTL, and has the advantage that the new home may be more congenial for both the plants (escape animals, insects and microorganisms which normally prey upon it) and the planters (lower transportation costs, more easily defended).
The Portuguese, Spanish, and Dutch are certainly able to play this game if they want to produce rubber for themselves. The Portuguese can transplant Hevea seeds from the Amazon to their holdings in Africa and Asia. The Spanish can demand those seeds from their Portuguese subjects, and then plant them in the Philippines. For that matter, they might be able to cultivate guayule in Spain. The Dutch and Portuguese can establish Manihot or Hancornia plantations in the drier parts of Africa or Asia. Or raise Funtumia in Brazil, or Trinidad (Christy 237).
The main limitation on these competitive activities is a subtle one; it is not worth the trouble of establishing a plantation if you will not be assured of a market for many years. Any down-time government which is astute enough to realize that natural rubber is desirable is also going to realize that at some point Grantville will be producing synthetic rubber. We can certainly play on their fears; they lack the experience in up-time technology which would allow them to estimate how soon synthetic rubber factories would come online.
By the same token, it may not be strictly necessary for us to establish rubber plantations. However, natural rubber is superior to synthetic rubber for tires.
Homegrown Rubber
The USE in 1632 is in a position somewhat like that of Russia during World War II, and therefore has an incentive to look at sources of natural rubber which, while they may not be economical in the long run, are less susceptible to disruption by enemy action.
CE mentions several rubber plants which grow in temperate regions: guayule, goldenrod (studied by Edison, it notes), and Russian dandelion. There is no reference in any of the "rubber" entries to milkweed, but I believe that it is reasonable to assume that Grantville residents would know that it exudes a latex when cut.
Guayule isn't likely to grow in northern Europe, and there are problems with obtaining guayule and Russian dandelion for planting purposes, so I expect that the domestic rubber production, if any, will be based on milkweed or goldenrod.
Milkweed
Over 100 species of milkweed are found in the United States. At least thirteen of them are native to West Virginia. The Monarch is the West Virginia state butterfly, and it lays its eggs on milkweeds. Thus, it is quite likely that milkweeds were actually cultivated in Grantville gardens, before the Ring of Fire, in order to attract Monarchs. But even if that was not the case, we can expect that milkweeds, being hardy and abundant roadside, thicket and pasture plants, accompanied the up-timers on their involuntary voyage to seventeenth-century Thuringia.
How many? We can make an estimate using USDA wild milkweed density data: 0.027 to 0.039/m2 (Maryland), 1.052/m2 (Wisconsin), and 3.604/m2 (Ontario), all for nonagricultural land. If the Ring of Fire had a three mile radius, then that is an area of about 28 square miles, or about 72,500,000 square meters. If half of that area were nonagricultural, with milkweed at the lowest density quoted—0.027—that would still add up to almost 1,000,000 plants.
Milkweeds have several advantages as a source of rubber. First and foremost, they will grow in the USE; we don't have to worry about running overseas milkweed rubber plantations. They are also extremely hardy; well suited for machine harvesting because the stalks grow tall and erect (Whiting, 24); and productive of other useful materials (see below) besides rubber. Finally, their rubber is equivalent in quality to Para rubber.
Their principal disadvantage is their relative low rubber productivity. Also, the rubber cannot be harvested without killing the plant, while Hevea trees can be tapped for several years. This second disadvantage is somewhat offset by the rapid growth rate of milkweed; the harvested plants will be quickly replaced, certainly by the following year.
The Russians experimented with A. syriaca during the Second World War, and they reported an annual yield of 100-150 kilograms of rubber per hectare, from a crop of two tons of leaves. (The rubber content is highest in th
e leaves, especially mature ones.) The necessary seed was about four to five kilograms per hectare. Of course, the up-timers are going to have to learn all this the hard way.
Because of its relatively low rubber yield, milkweed rubber never became a commercial product. However, the labor costs of producing it are somewhat offset by the possibility of extracting a second useful product from the crop. In 1746, Germans began using the seed hairs (floss) as padding material. In 1918, it was suggested that it could be used as a substitute for kapok, a silky fiber, with excellent buoyancy, used for stuffing and insulation. (Whiting) During World War II, Americans collected 11 million kilograms of pods, filling 1.2 million "Mae West" life jackets (Witt). About 24% of the pod is floss. The reported average annual yield of floss from wild milkweed is, depending on who you ask, 187-349 (Witt), 550 (Whiting) or 1,368 (Duke) kilograms per hectare.
Harvesting the widely scattered wild milkweeds would not be productive. However, we can collect their seeds, and then plant them in rows. Each stalk has four to six seed pods, each pod contains, on average, 220 viable seeds. One hundred seeds weigh about 42-73 milligrams. (DeGooyer) Based on the Russian seeding data, we need about 100,000 seeds per hectare—the seed production of 1,000 stalks. The first plot would probably be an experimental plot where the up-timers experiment with different spacings, seed times, fertilizers, and so on. They would begin production farming in the second year.
The up-timers don't know which parts of the milkweed plant have the highest rubber content, so they will have to find this out by trial and error. The leaves provide more rubber than the stems; yellowing leaves provide more than young leaves, and autumn leaves provide more than spring or summer leaves.
Milkweed latex has a fairly high resin content (perhaps 9-23%). Several methods of recovering the rubber were developed in the old timeline. Kassner treated the latex first with benzene or carbon disulfide, and then with alcohol and caustic lye. After each solvent addition, he distilled. The rubber was the final residue. Hall and Long used boiling acetone, followed by boiling benzene. Students in a modern introductory organic chemistry lab used acetone to extract various impurities and then cyclohexane to extract the rubber. (Whiting, 20-23; Volaric)
None of this will be known in Grantville. Up-timers will probably first try a simple hot water treatment of chopped-up plant material. If they don't like the properties of the rubber, they will probably then just experiment with different solvents until they get results that they like.
Of course, organic solvents are going to be in short supply until we can extract the necessary compounds from coal or oil. The most readily available organic solvents will be ethanol and acetic acid. And any solvent treatment step is going to increase production costs.
It may be possible to cure the resin content problem at its source by breeding milkweed for low resin content (this of course assumes that you have a way of measuring resin content!). I have also come across a hint that in the 1930's, the Russians found a method of chemically treating the plant so that it produced latex with more rubber and less resin. (Whiting, 18)
Goldenrod
Thomas Edison devoted the last four years of his life (1927-31) to an attempt to develop a method of producing rubber from domestic plants. Edison ultimately settled on the goldenrod, because "it would grow in most parts of the country, it grew to maturity in just one season, and it could be harvested by machines." He increased goldenrod rubber production several-fold by breeding methods, although his technique was not "cutting edge" (Vanderbilt 316) and could certainly be improved upon by a modern breeder with access to a variety of material.
Goldenrods originated in Europe. There are about two dozen species of goldenrods found in the wild in West Virginia, and thus, presumably, in the land transported by the Assiti shard. Since goldenrod is an ornamental plant, there may be additional varieties in Grantville gardens. We can collect the latex from as many different species as we can find, and decide which species is the best rubber producer. Edison preferred Solidago rugosa and Solidago leavenworthii, but this would not be known in Grantville. Nor will anyone know what to expect in terms of yield, unless someone has an informative Edison biography in his or her personal library. (Edison's results are set forth in Table 2.)
Likewise, it will be necessary to reinvent the methods developed by Edison for harvesting the plants (he wanted to just collect the upper leaves, since they have the highest rubber content) and for recovering the rubber from the latex (he used acetone to pull out the resin, and then benzene or benzol to extract the rubber). The solvents can be recycled. (Baldwin, 398; Vanderbilt, 313)
My thinking is that goldenrod will be grown and harvested primarily as a source of yellow dye, with any rubber production being strictly a bonus. The trick will be to identify a variety that is a good dye source and a good latex source.
Rubber Reclaiming
In 1910, when the price of rubber was high, about half of all of the rubber sold was reclaimed. (Reschner)
Rubber is going to be in high demand, and the only immediately available source of rubber is scrap rubber. Since more than half of all modern rubber goes into tires, the latter are also the foremost source of scrap. An automobile tire weighs about twenty pounds. Of this, about 60% is recoverable rubber. (tfhrc.gov). A truck tire weighs twice as much as an automobile tire, and has a proportionate rubber content.
The residents of Grantville are likely to look first at tires that have been discarded or set aside. These may be in dumps, landfills, garages, backyards, and so forth. The rule of thumb is that modern Americans generate scrap rubber at a rate of one passenger tire equivalent per person per year.
Unfortunately, there is a catch. Grantville is based on the real town of Mannington, West Virginia . . . and its dump was not within the Ring of Fire (Boatright, Grantville Gazette, Vol. 1). So we have to hope that the GV residents were not efficient about setting out their used tires for pickup.
There may also be small amounts of rubber that can be recovered from rubber goods that are no longer useable for their original purpose. Personally, I think that is going to be a real small supply.
Hence, at a relatively early stage, the USE will need to decide whether to scrap some of the auto tires (figuring that it cannot keep the whole auto fleet running) in order to supply patch material for the heavy tires used in the USE's military vehicles.
At the very least, all the spare auto tires in the car trunks can go to the rubber reclaiming plant. If there are around 1,200 cars (Mannington actually has more than that), then that will potentially yield 24,000 pounds of tires, and about 14,000 pounds (seven tons) of somewhat degraded rubber. If we decided to take the working tires off half those cars, that would be another 48,000 pounds of tires, and thus another fourteen tons of secondhand rubber.
One problem is that the Grantville encyclopedias are not very specific about the methods used for rubber reclaiming. EA suggests that the rubber is mechanically reduced to scrap, which is then "heated with steam in the presence of strong chemicals, mainly alkali or acids."
If someone does have the Microsoft Encarta on CD, that gives additional information. It mentions the Chapman Mitchell process, in which hot sulfuric acid is used to destroy tire fabric and restore rubber plasticity, and the Marks "alkaline-recovery process."
In general, the rubber is not going to be restored to its original unvulcanized state, and hence it is more difficult to use. Usually, the reclaimed rubber is used as an extender, together with fresh rubber.
Proposal
Our initial natural rubber industry development strategy should be:
(1) use rubber substitutes (e.g., leather) whenever possible;
(2) conserve and reclaim up-time rubber;
(3) cultivate milkweed at home;
(4) send raiding parties into central America to collect Castilla rubber; and
(5) attempt to reach the Hevea rubber of the Amazon by a back-door route.
Once we have built enough steamships (warshi
ps as well as merchant ships) so we can spare a few for extra-European ventures, we should send an expedition-in-force to the Amazon to collect Hevea seeds, and then one to Africa or Asia to establish plantations and collect wild rubber (and rubber tree seeds). Ideally, we would also have sufficient medical resources so as to offer this expedition some protection against the many diseases that hamper seventeenth-century international trade.
If we are allowed to trade freely for wild Brazilian Hevea rubber, and to promote efficient tapping practices, it should satisfy our needs for rubber up until annual world consumption reaches the 30,000 to 40,000 pound range (the peak Brazilian wild rubber production). After that, the development of alternative rubber sources is essential. Hence, at the end of the first decade, we need to decide whether to establish Hevea plantations in Africa or southeast Asia, or to pursue synthetic rubber.
While an investment in the rubber industry is definitely going to qualify as one of USE's riskier commercial ventures, investors can at least be confident that if they are successful, the USE government and private industry will be sitting on their doorstep, anxious to do business.