OUR STAR – THE SUN
There are nine planets in the solar system:
What do you know today of the nearest star which lies 150 million kilometres away?
The Sun is a mass of flaming matter, the temperature at its surface is above 5,500 degrees Centigrade, the temperature in the Sun’s centre is as high as 20 million degrees Centigrade. The Sun’s diameter is 109 times that of the Earth and its mass is 330,000 times greater.
The illumination of the Earth by the Sun is 10 billion times stronger than that by Sirius, the brightest star of the northern hemisphere. But this does not mean that the Sun is bigger than Sirius: it is simply nearer the Earth.
Nine planets with their satellites revolve round the Sun due to the force of universal gravitation. It takes our Earth a little more than 365 days to revolve round the Sun.
The Sun is the most important body in the Universe for mankind. It provides us with light during the day and the light of the Moon is only the reflected sunlight.
It is also important that the Sun gives us heat without which no life can exist on the Earth. It provides us with all the energy that we use every day.
When we look at the Sun, it seems a fire ball. But even from a brief acquaintance with some of the solar phenomena it is clear that the Sun is an ever boiling ocean. The Sun is a giant natural hydrogen bomb, equivalent to millions of man-made ones where the thermonuclear reaction proceeds continuously.
It is interesting to note that every second the Sun sends into space as much energy as mankind consumed during the whole period of its existence from the first fire of the cave-man to the establishment of the atomic power station.
Solar energy has great value to mankind.
Man has tried to use solar energy since the earliest times. Methods of using the light and heat energy from the Sun are not new, but they are not very efficient as yet.
It is necessary to find effective methods of utilizing this immense supple of free energy, to make our star – the Sun – serve mankind.

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 bench 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 machine 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 of 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 production and will serve to increase the productivity.
The USSR and other highly industrialized countries begin making use of flexible modules and automated workshops on a broad basis.

IN THE CHEMICAL LABORATORY
Look at the picture!
Here is our chemic