Later in the morning the workers make the rounds of the trees with large milk cans, gathering the latex from the cups. When the cans are full they are carried to a collecting station, called a Coagulation Shed. It is as clean and well kept as a dairy. Here the latex is weighed, and when each collector has been credited with the amount he has brought, it is dumped into huge vats.

The next step is to extract the particles of rubber from the latex and to harden them. The jungle method of hardening rubber is to dip a wooden paddle in the latex and smoke it over a fire of wood and palm nuts.[3] It is a back-breaking process to cover the paddle with layer after layer, until a good-sized lump, usually called a "biscuit," is formed. The plantation method is a quicker and cleaner one. Into the vats is poured a small quant.i.ty of acid, which causes the rubber "cream" to coagulate and come to the surface. The "coagulum," as it is called, is like snow-white dough. It is removed from the vats and run in sheets through machines which squeeze out the moisture and imprint on them a criss-cross pattern to expose as large a surface as possible to the air.

[3] See picture, page 12.

These sheets of rubber are then hung in smoke houses and smoked from eight to fourteen days in much the same way that we smoke hams and bacon. After being dried in this way they are pressed into bales or packed in boxes ready for shipment.

CHAPTER 8

A LAST WORD

It would be an adventure to follow a bale of plantation rubber as, carefully boxed or wrapped in burlap, it starts on its long and picturesque journey. Bullock carts, railroads, boats and steamers bring it at last to one of the world markets, Singapore, Colombo, London, Amsterdam or New York, where it is bought by dealers, and then sold to factories which make rubber goods.

An equally fascinating story might be told of its progress through the factory, how it is kneaded and rolled, mixed with chemicals, rubbed into fabrics, baked in ovens, and finally emerges as any one of the tens of thousands of articles that are made wholly or partly from rubber.

Rubber manufacturing is peculiarly an American industry. South America gave us the original rubber trees, and the one man who, more than any other, was responsible for making rubber useful was the American, Charles Goodyear. To-day, two-thirds of the entire output of rubber is sold to the United States, whose manufactured rubber goods set the standard for the whole world.

In spite of the wonders which rubber has already accomplished, and the adventures, which have colored its history, only the beginning of the romance of rubber has been told. The plantation industry is still in its infancy, and experiments are constantly being made to determine the best methods of planting, the most fruitful number of trees to the acre, the most advantageous way of tapping. In the laboratories of the great rubber manufacturers, scientists are at work improving old methods of using rubber and devising new ones.

Rubber is a substance of so many important characteristics that its uses are countless. It is used for certain purposes because it stretches, for others because it is airtight and watertight, for others because it is a non-conductor of electricity, for others because it is shock-absorbing, and for others because it is adhesive.

It is on rubber that infants cut their teeth; after all the teeth are gone old age makes use of rubber in plates for false teeth.

Ten million motorists and other millions of cyclists in the United States ride on rubber tires that are durable, noiseless and airtight. Balloons of rubber float aloft, and huge submarines plow their routes beneath the ocean's surface propelled by electricity stored in great rubber cells. Sheathed in rubber, the lightning makes a peaceful way through our homes, offices and factories, furnishing light and telephone service. Divers sink out of sight beneath the waves in rubber suits. Rubber air-brake hose on railroad trains makes safe the travel of a nation, air-drill hose rivets our ships, fire hose protects the properly in city and town and garden hose brings nourishment to our growing plants. Rubber clothing protects against storm and rubber footwear guards us against cold and wet. Tennis b.a.l.l.s and golf b.a.l.l.s and rubber-cored baseb.a.l.l.s give healthful sport to the millions. In hospitals and medical work the uses of rubber are without number.

To select the most important use to which rubber is put would be difficult. One student of the subject says:

"Of all the applications of rubber, that of packing for the steam engine and connecting machinery appears to have been the most important, as it has been an essential condition of the development and extended use of steam as a motive power."

Even as you read this, rubber may be in the act of performing some new magic, some fresh service to mankind. And who knows which one of us will, in the years to come, write a chapter in the story of rubber more thrilling than we are able to imagine to-day!

A REVIEW AND QUESTIONS

1. Who was the first white man to see rubber?

2 What use were the natives making of it?

3. Who was the first white man to go up the Amazon?

4. Of what nationality were the explorers who were sent to find out about rubber?

5. Who was the first European monarch to use rubber?

6. How did rubber get its name?

7. How did rubber first come to the United States?

8. Why are some raincoats called mackintoshes?

9. Why is Charles Goodyear called "the father of the rubber industry"?

10. What is "vulcanizing"?

11. What famous men fought in court over the patents?

12. What has a beetle to do with rubber?

13. Name and describe the liquid in which rubber is found?

14. In what part of the tree is this liquid found?

15. What is the difference between this liquid and the sap of a tree.

16. Name and describe the best rubber tree.

17. How are the seeds spread?

18. What climate is needed for rubber trees?

19. Which country formerly supplied all the rubber used in the world?

20. Who first thought of growing rubber trees on plantations?

21. Why did he think it was better to grow them on plantations?

22. How were the rubber seeds taken from Brazil?

23. On what tropical island was the first plantation started?

24. Where are rubber plantations found to-day?

25. What is the yearly output of the plantations?

26. What was the curious coincidence in the growth of the plantation industry?

27. What is meant by the Rubber Belt around the world?

28. What countries are the princ.i.p.al producers of rubber?