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TRANSMITTING PICTURES BY TELEPHONE

Pictures can now be sent over the telephone by sound signals. A new machine does this by looking at a picture and telling what it sees over the telephone to a similar machine at the receiving end, which then translates the sound signals it hears back into the form of a picture.

At the sending end, the photograph, drawing business form or document is placed in the machine. At the receiving end, the reproduction appears on ordinary paper. An illustration of ordinary letter size takes six minutes to be received and reproduced.

This is how the machine works.

Inside the machine optical devices rotate and pick up reflected light which is focused on and passed through a filter to a photocell or "electronic eye". The photocell generates a signal which is amplified to produce voltages of varying strength.

The voltages are converted into sound, and it is this audible signal which is transmitted over the telephone, just as music or voice is transmitted.

At the receiving telephone, the sound is reconverted to an electronic signal and then into a varying voltage. This voltage is applied to a drive mechanism. The mechanism is activated to extend and print out a corresponding dark area of the transmitting picture. The length of the document determines the time needed for transmission.

Memorize the following words and word-combinations:

1.sound

2.similar

3.send

4.receive

5.appear

6.photocell

7.optical device

8.voltage

9.transmit

10.is reconverted

Answer the questions:

1.How the picture can be sent?

2.How does the new machine do it?

3.What is done at the receiving end?

4.What are the devices inside the machine?

5.What is converted into sound?

 

TEXT 11

EVOLUTION OF THE COMPUTER

(part 1)

I. Rend and memorize the following words and word-combinations: electronic computing machine -

advanced -

brain work -

reliably -

forecast -

scope -

research establishment -

accounts department -

man's muscles -

human being -

same -

to play an important role -

fast -

cheap -

aircraft design -

a few -

undoubtedly -

to widen -

II. Rend and translate the following text:

Not many years ago the electronic computing machine was little more than a highbrow laboratory instrument, to be found only in the more advanced mathematics departments of universities or government research establishments.

Nowadays it performs nearly all the functions of a large commercial accounts department These machines are constructed on -the best engineering principles.

But what is the reason for this sudden popularity? The answer is of course, that a new and advanced form of mechanization is beginning to appear in industry and commerce - mechanization of brain work.

Whereas in the Industrial Revolution it was man's muscles that were replaced by mechanical power, in this latest phase, which we sometimes call the Second Industrial Revolution, we see machines taking over some of his simpler mental processes. It is uneconomic to employ human beings, when there are machines which can do the same operations faster, cheaper and more reliably.

Aircraft design, ballistics, crystallography, electron optics, astronomy, pure mathematics and weather forecasting are just a few of activities in which computing machines are playing an important role. And the scope will undoubtedly widen in the future.

Answer the questions:

1. What was the electronic computing machine not
many years ago?

2.Where could they be found?

3.What was replaced by mechanical power, in the latest

phase, which we sometimes call the Second Industrial Revolution?

4.What machine is economic to employ instead of human beings in taking over some of their simpler
mental processes?

5.In what activities does the computer play an important role?

 

TEXT 12

Read and translate the following text:

Calculating machines as such are by no means new, of course. If one leaves out the abacus or counting frame, which appeared long before Christianity, they are about 300 years old or more: John Napier, a Scot, must be given credit for paving the way, at the beginning of the 17th century. He did not devise a system of numbering rods as an aid to multiplication (known as Napier's bones) but was the inventor of logarithms, which were almost immediately embodied in the slide rule.

The bones were an elementary aid to digital calculation while the slide-rule was probably the earliest analogue device and these represent the iwo main streams in computing technology as we know today.

Napier's bones*, however, had no real practical value, and were little more than a scientific curiosity. It was a Frenchman, Blaise Pascal, who achieved the first successful mechanization in 1642. His machines consisted of a series of wheels with numbers round them,] the first wheel representing units, the second tens, the third hundreds, and so on, and it worked on the same sort of principle as the modern revolution counter. Although it was a very simple device it contained one important development which is an essential part of digital computing technique - a means of making the <carry over used in adding numbers together, into an automatic process. Moreover, it showed the possibility of multiplying numbers by successive addition-another principle used in modern computers and this was actually embodied in a machine by Leibnitz in 1871. From then onwards a variety of improved calculating machines were devised all based on the original idea of wheels moved round in steps, and in the 19th century commercial models began to appear.

Memorize the following words and word-combinations:

1.calculate

2.abacus ,

3.numbering rods

4.inventor

5.embody

6.bones

7.value

8.wheel

9.adding

10.multiplying -

 

Answer the questions:

 

1. When did the abacus or counting frame appear?

2. What can you say about Blaise Pascal's first successful mechanization in 1642?

3. What important development did this very simple
device contain?

4. What another principle used in modern computers
was embodied in a machine by Leibnitz in 1691?

5. Did commercial models begin to appear in the 18Lh or
the 19th century?

 

TEXT 13

 

 

. .

The Science of Mechanics

Mechanics deals with a variety of problems, but notwithstanding this variety they fall under one of the following classifications:

1 .Determining the trajectory described by the points of a moving body, the position of any one of the points in its trajectory, its speed and acceleration, etc., in short, the solution of any of its individual points of the trajectory, its speed and acceleration, etc., in short, the solution of any of its individual points independent of the force applied.

This branch of mechanics is called kinematics. Kinematics deals with the relationship between the geometric elements of motion and time, irrespective of the forces acting on the body in motion.

2.Determining the nature of motion of a body as related to the forces acting on the body, or, conversely, determining the forces causing the motion. This type of problem is dealt with in the branch of mechanics called kinetics.

Mechanics also treats of terrestrial bodies in a state of rest, that is, a state of equilibrium. Here we seek the conditions under which forces acting on a body are brought into equilibrium, for knowing these conditions, engineers can ensure rigidity and strength to the structures they are building.

That part of kinetics dealing with equilibrium of forces and the consequent state of rest of a body is known as statics, while the investigation of motion of bodies under the action of forces applied to them constitutes another branch of kinetics called dynamics.

Such are the sciences embraced by mechanics, and their fundamentals are tought in the following order: statics, kinematics, and dynamics.

TEXT 14

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