Text A

RUBBER

When Columbus landed in the New World, he found that the natives were playing with heavy balls made of some sort of vegetable gum. Later explorers found that the Aztecs used similar balls in a game that was some­thing between basket-ball and tennis. Though many visitors to these parts reported on this material, it remained more or less unknown for nearly three hundred years. Then, in the eighteenth century a Frenchman took a great in­terest in its production and applica­tion and stimulated others to study the material. An English chemist discovered its first practical use — the rubbing out of pencil marks — from which its English name "rubber" was derived. The main difficulty hindering further ap­plications was the problem of producing a uniform, stable product from the milky liquid obtained from the rubber tree.

The difficulty was overcome only when a study of the white liquid was taken up in the later part of the nineteenth century. In 1873 seeds of rubber-producing plants had been sent from the Amazon region to the Kew Botanical Gardens in England. Then, they were sent to Ceylon and Singapore and formed the beginning of the new rubber plantations in India, Malaya and the East Indies.

In the meantime, scientist had tried to adapt this elastic material to technical uses. In 1834 a primitive type of vulcanization was discovered—a process of transforming the soft natural rubber into a harder, more durable solid. Vulcanization was greatly improved when a fortunate accident led to the perfection of this method: during an experiment a mixture of soft rubber and sulphur was dropped on a hot stove.

Later on the problem of vulcanization was solved by mixing crude rubber with mineral powders, oils and fibres. Then, to meet the fast-rising de­mand in automobile tyres, the technologists began an extended research into the chemistry of synthetic rubber.

Grammar and lexical exercises

I. Define the functions of the ing-forms and translate the following sentences into Ukrainian.

1. The growth of learning in Europe in the second half of the seventeenth century brought an important change in chemistry. 2. It took thirty years of experimental work to work out the process for purifying the metal aluminium. 3. The temperatures at which a substance melts and boils are called its melting point and its boiling point. 4. Boiling water changes its state. 5. Many bacteria cannot live at the temperature of boiling water. 6. Chemical methods of purifying water are becoming very important. 7. One of the ways of obtaining salt is evaporating sea water. 8. Evaporating sea water we must observe the rising of the temperature. 9. If we raise the temperature for the amount of water which we are evaporating, the process will advance at a higher speed. 10. A burning-mirror is a mirror for producing heat by concentrating the sun's rays. 11. The preservation of building stone is of great importance in architectural work. 12. One of the methods of preserving fruit is drying. 13. What is drying in the drying-room?

II. Define the - ing forms and translate the sentences into Ukrainian.

1. Experts predicting the exhaustion of the supply of fossil fuels base their prediction on the present rate of increase in energy. 2. Predicting the exhaustion of the supply of fossil fuels experts take into account the present shortage of energy in many developed and developing countries. 3. Making predictions is great responsibility. 4. The exact knowledge of the present state of affairs is necessary for making predictions. 5. We can use solar energy by converting it to electricity.

III. Define the functions of the ing-forms and translate the following sentences into Ukrainian.

1. They tried to make the philosopher's stone by distilling a mixture containing urine. 2. They used a better method of obtaining the element. 3. Some investigators produced phosphorus by heating its compounds to very high temperatures with carbon. 4. The famous English scientist Robert Boyle managed to prepare phosphorus and he taught his method to Godfried Hankwith. 5. For many years only Hankwith managed to make phosphorus in any quantity and he supplied it to the whole of Europe.

IV. Translate the following word-combinations into Ukrainian.

to gain in speed; to lose speed; to need extra parts; to combine work and studies; to lose time; at a distance of nearly two miles; to observe weather changes; on the upper shelf; low clouds; to move very fast; the density of the atmosphere; the advantages of the new aircraft design; to fit extra seats; things urgently needed for medical help; a strong water flow; to convert work into energy; a skilled worker; available extra parts; to recognize the trouble in the engine; densely-populated countries; this fact alone; to take precautions against engine breakdown; to be capable of solving complicated mathematical problems.

V. Translate the following word combinations into Ukrainian.

Outstanding invention; outstanding writer; no doubt about it; to have no concern; a fallen tree; to evolve a theory; supporting beam; to get no support; to rope a box; to support a family; to lay bricks; to be secure from danger; to secure freedom; to prevent an accident; to prevent war; a bridge pile; to drive piles; the fall of an apple;

civil engineer; a number of projects; although it was taken into consideration; local transport; a suitable person; the width and the depth of the river; to erect buildings; to distribute books; to acquire experience; circular cross-section; to suggest a scheme; to agree to such a schedule; actually different; to object to the condition; the layers of the soil; numerous cracks; to penetrate rapidly; to estimate the cost; to share losses; so far unknown; to mention the same fact.