Machine Tools – a Measure of Man's Progress

The variety and combinations of machine tools today are unlimited. Some of them are very small and can be mounted on a work-bench¹ but others are so large that we have to construct special buildings to house them.

There are some basic operations at any workshop. They are turning, drilling, threading, etc. The main machine tool of such a workshop is the multipurpose lathe. What is a lathe? It is a power-driven machine² with special tools which can cut or form metal parts. The metal that cuts another metal must be very hard and so tools should be made of very hard steel alloys. The tool itself is very small in comparison with the mechanism that is to direct it.

Technological progress improves accuracy of machine tools. Today's equipment can produce parts with very high accuracy. One can find a number of³ machine tools that can measure and inspect their production themselves – machine tools that are to handle the parts mechanically and automatically.

Such machines can hold the parts which are to be measured and are able to indicate precise measurements themselves. A great many of such "clever" machines can be found today in our industry.

Since machine tools become faster and more complex, automatic measurements and inspection ought to be of greater importance. Automation is one of the main factors of engineering progress.

Flexible production lines form the basis for automated workshops. The main principle of such a flexible line is the fact that it can be switched over from one product to another, which has a similar structure but a different outline, almost instantaneously. It is equally efficient in conditions of both mass and small-batch production⁴ and will serve to increase the productivity.

Notes on the text

¹ work-bench – верстак

² power-driven machine – станок с механическим приводом

³ a number of – ряд, несколько

⁴ small-batch production – производство маленьких партий продукции

Task 1. Find modal verbs and their equivalents in the text.

Task 2. Answer the questions:

1. What types of machine tools are there nowadays?

2. What are the basic operations at a workshop?

3. What is a lathe?

4. Why must tools be made of very hard steels and alloys?

5. Is the tool itself big or small?

6. What improves the accuracy of machine tools?

7. What is one of the main factors of engineering progress?

8. What forms the basis for automated workshops?

9. What is the main principle of a flexible line?

Read and translate the text.

Compounds and Elements

All the substances which occur in nature consist of one or more basic elements; a substance containing more than one element is known as a compound.

An element is a substance that can neither be decomposed (broken into a number of other substances) by ordinary chemical action, or made by a chemical union of a number of other substances.

A compound consists of two or more different elements in combination and has properties different from the properties of its constituent parts. Water, for example, is a compound of oxygen and hydrogen.

A molecule is the smallest amount of a substance that can retain the characteristic properties of that substance and may consist, for example, of two atoms of hydrogen and two atoms of oxygen for hydrogen peroxide, of one atom of oxygen and one atom of carbon for carbon monoxide and of two atoms of oxygen and one atom of carbon for carbon dioxide.

An atom is the smallest unit of which a chemical element is built. The atoms of any particular element all have the same average mass and this average mass differs from the average mass of the atoms of any other element.

Task 1. Find the key words in the text.

Task 2. Make up your own questions to the text.

Revision exercises: