Match the following word-combinations with their definitions.
Student independent study: 1) Machine-tools – a measure of man’s progress Since man first picked up a stone and used it as a tool and weapon he began to develop and improve his tools. The replacement of stone tools by metal ones thousands of years ago was a great step in man’s progress. Only metal tools could lift man out of the Stone Age into the Bronze Age, then into Iron and Steel Age. The development of machine-tools accelerate d the industrial revolution and resulted in our modern industrial civilization. What is a machine-tool? It is a power-driven machine with special tools which cut or form metal parts. The metal that cuts another metal must of course 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. Today every product is a product of machine-tools. It is probably true to say that without machine-tools modern civilization cannot exist. The variety and combinations of machine-tools today are almost unlimited. Some of them are very small and can be mounted on a work bench, but others are so large that we have to construct special buildings to house them. Some machine-tools, such as presses, are very heavy and weigh several hundred tons. Technological advances improve the accuracy of machine-tools. Today’s equipment can produce parts with very high accuracy. One can find a number of machine-tools that can measure and inspect their production themselves – machine-tools that are to do this work mechanically and automatically. Such machines can hold the part which is to be measured and are able to indicate precisemeasurements themselves. A great many of such “clever” machines can be found today in our industry. Since machine-tools become faster, more complex, and automatic, automatic measurements and inspection ought to be of greater importance. Automation is one of the main factors of engineering progress. In our country there are some almost fully automatic enterprises: power stations with remote control, chemical plants where man must only look after automatic units, in metallurgy automation makes it possible to regulate processes automatically. The number of automatic plants will continue to grow. Modern civilization is also dependent on metallurgy which provides materials for future advances.
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