In the district we have come to visit, several Mexicans are busy gathering in a harvest of guayule. As you watch them at work, you notice that they pull up some of the shrubs by the roots, but others they pass by. No, the plants they leave in the ground are not by any means poor specimens; they are young guayules, as yet under 18 inches high, which are being left to grow and furnish another crop.
Presently we espy quite a number of donkeys coming leisurely along towards us over the plain. They have been down to a packing-shed close by with a load of guayule, and are now returning for another load. When they reach the harvest-field, great bundles of the shrub are piled up on their backs, until we can hardly see anything of the useful little beasts but a row of heads and an array of paws. However, their burden is not so heavy as its bulk would have us imagine. We follow the caravan of donkeys to the packing-shed and see them unloaded. Then we watch the guayule being pitched by hand into crates and tightly jammed therein by being jumped on by the packers. When the bales are taken out of the crates they remind us of trusses of hay. The bales are weighed, stacked in carts, and taken to the factory.
Seated on a bale in one of these carts, we, too, go to the factory. Here we see the crop of guayule being crushed between rollers, and for the moment we are reminded of a sugar-mill. The crushed plant, a mixture of bits of wood and atoms of rubber, is conducted to a pebble-mill, which is a drum half filled with stones and water. The mill is rotated, and the rubbing action which is thus set up rolls the rubber into larger pieces and grinds the wood to pulp.
The mixture is now pumped into large tanks. The rubber, being lighter than water, floats; the wood, being heavier, sinks. The rubber is skimmed off and purified, after which it is washed and put into bags ready to go to market.
Guayule rubber is of sufficiently good quality to be used for all but the highest class rubber goods, such as surgical appliances.
[CHAPTER IX]
DIFFERENT KINDS OF WILD RUBBER—continued
The chief wild-rubber producing countries in the Old World are Africa, Northern India, and the East Indies.
In Africa, the rubber-giving plants are the Funtumia elastica, a medium-sized tree, and several varieties of vine whose family name is Landolphia. Both plants flourish in the tropical forests of West Africa, extending from Soudan to the Congo, and embracing large areas in Liberia, Gold Coast, Southern Nigeria, and the Cameroons. Landolphias grow profusely in these same forests, and in the more northerly West African districts of Senegal, Gambia, and Sierra Leone; they also abound in British East Africa and neighbouring territory.