Reading Without Understanding the Meaning of Every Word

The following selection will probably contain a number of words you do not know. This is not surprising. English has a larger vocabulary than any other known language. Later on in this book you will learn more vocabulary and, more importantly, skills of guessing the meaning of new words from their con­text or form.

Right now, practice the important skill of reading without knowing the mean­ing of every word by following these steps:

1. Look over the entire selection quickly, paying attention to the first
sentences of each paragraph and trying to get a general idea of the
contents of each one.

2. Read the selection for the main ideas. Skip over words and phrases
you don't understand. Do not slow you slow down by looking words
up in a dictionary. Keep going.

3. Do the exercise called Recalled Information (it follows the text). If
you have trouble with it, read the text (or parts of it) again. You will
probably understand it better this time. Two or three quick readings
are better for understanding than one slow one. Once you have
worked the exercise, you have read well enough for your present
purpose.

What is Oil?

1 There is magic in oil, that smelly black liquid which forms greasy
puddles on the garage floor.

2 Gasoline, the main product of crude oil, or petroleum, runs our
cars, trucks, buses, and boats. Before the day of our swift transporta-­
tion, people travelled in horse-drawn vehicles, or by train.

3 The oil used for heating is another product of petroleum." Natural
gas found with petroleum, is burned in millions of kitchen stoves. Still

12 Chapter One

other petroleum products, called petrochemicals, are used to make paints, cleaners, waxes, medicines, and hundreds of other things.

Abundant sea life helped form petroleum beneath the ocean floor.

Crude oil is a black, heavy liquid made up almost entirely of two elements -i-hydrogen and carbon. Hydrogen is a gas. Carbon is a solid which we know best as charcoal or the graphite in lead pencils. When these two elements are combined in the right proportion, together with atoms of other elements, a liquid called petroleum, or crude oil, is formed.

This combination of atoms took place inside the earth mil­lions of years ago. In prehistoric days, great fires in the centre of the earth exploded the cooling outside crust into huge piles, forming continents and moun­tains ranges. Thousands of years later the rock was soft­ened and crumbled by wind and rain until plants could grow. Swamps sheltered strange fish,

Typical fossil remains.

great scaly snakes, lizards, and dinosaurs.

The History of Oil

The earth's uneasy surface was still being churned by earthquakes and volcanoes. Whenever such an eruption occurred, much vegetation and billions of animals and fish were buried deep under mud, washed down by violent rains. As time passed and more sand and mud flowed down, the enormous weight squeezed the bottom layers until they turned to stone. The partly rotted animals and plants trapped between the layers of stone were changed by heat and pressure. In some cases coal was formed. In other layers, especially when sea creatures were present, oil was formed.

This oil was forced by the enormous pressure from above into the tiny pores of soft rock like sandstone or limestone. The oil was pushed along through the porous rock by the pressure of water which has also seeped in. The water forced the oil ahead of it until it reached hard rock which it couldn't pass. Here it stayed, trapped in an oil pool, along with a certain amount of natural gas.

Sometimes oil found its own way to the surface through cracks in the stone layers, usually along with springs of water. Oil from one area is often quite different from that found in another. Some crude oil contains much gasoline, while another sort is rich in lubricants. One type will have an asphalt base; another will have a paraffin or wax base. Some oils are very dark, others are light. Even the weight dif­fers.

After You Read