Earlier, in the pre-computer era, people used a wide variety of auxiliary tools for counting and calculating. One such instrument was the arithmometer. It speeded up the calculation process, but required certain knowledge and skills from the user.
What is
In the USSR, the calculating machine was the "Felix" adding machine. This ingenious calculating device was a real mechanical computer. He could perform four basic operations: subtraction, addition, division and multiplication. He could work with numbers up to 9 registers long, and give the result up to 13-digit numbers. That is, with numbers that not every modern calculator can handle. However, it was difficult to work with him. It weighed a lot - 3.5 kg - and took up space on the table like an old computer with a CRT screen. He performed only the simplest counting operations, but at the same time, in order to make calculations, he had to perform complex algorithms.
Felix adding machine was produced from 1929 to 1971. Since it was the main computing tool used in many areas of the national economy, all Soviet schoolchildren underwent a mandatory training course to work on this device, just likethe same way as today's schoolchildren are taking computer lessons.
The machine can perform four simple counting operations: addition, subtraction, multiplication and division. Some experienced specialists (accountants, design engineers), who had to work long and hard with it, even managed to calculate percentages and the root of a number on it. How to use the Felix adding machine and make calculations is described below.
Addition
Addition is one of the simplest operations you can perform. For example, you need to add the numbers 456 and 340. The calculation algorithm is as follows:
- Zero out by rotating the lambs (located on the sides at the level of the carriage) all the numbers on the carriage. The handle should be in a fixed position, as shown on the "Felix" adding machine (see photo above).
- Move the carriage lever to the left.
- Dial the first number on the drum by setting the levers opposite the numbers. You need to start from the right edge.
- Turn the handle clockwise one full turn.
- The number 456 should be displayed at the bottom of the carriage to the right in the results counter. One will appear in the left carriage windows. If this does not happen, reset to zero and enter the number, as described above, again.
- Dial the second number on the reel using the levers.
- Turn the crank clockwise one turn and the result of the addition will be displayed on the carriage.
Reset to zero in subsequent calculations, if the result of the previous one is used, notnecessary. Thus, you can add entire columns of numbers, entering more and more new numbers, and each time turning the pen.
Subtraction
The algorithm of the "Felix" adding machine when performing a subtraction operation is similar to the addition process, only the handle will need to be turned in the opposite direction. Below are the steps you need to take to subtract 240 from 500, for example.
- Set the handle to its original position, reset the numbers on the carriage.
- Enter the number 500 on the drum and turn the knob one turn clockwise.
- Enter the number 240 on the drum and turn the knob one turn counterclockwise.
The result of the subtraction should be displayed at the bottom right in the answer window located on the caret.
Multiplication
The algorithm for multiplying 45 by 56 is shown below.
- Set the adding machine to its original position.
- Enter the number 56 on the reel.
- Move the carriage one register (there is a lever at the bottom) and make 4 turns of the crank clockwise.
- Return the carriage to its original position and make 5 turns clockwise.
On the left, on the revolution counter, the number 45 should be displayed, and on the right, the result of multiplication.
Division
This is one of the most complex operations performed on the "Felix" adding machine. Below is an algorithm of actions that must be performed to divide 4455 by 355.
- Reset the calculating machine.
- Move the carriage to the far right.
- Set the number 4455 using the far left drum levers. Start with 13 slots.
- Turn the knob clockwise. This number should appear in the results window on the left side.
- One will be displayed in the revolutions window, reset it by turning the left lamb.
- Set the number 355 with the levers opposite the dividend 4455. In other words, set the number 355 using the far left drum levers.
- Move the carriage one register to the left and rotate the drum counterclockwise until it rings.
- Then make one turn clockwise, then move the carriage to the left one more register and make a turn counterclockwise until the bell rings.
On the caret in the left window you will see the quotient 12, and on the right side of the caret you will see the remainder 195. If you need to calculate to hundredths, then add two zeros to the number 4455 and continue dividing, as described above. Separate the added zeros on the letter with a comma. The arrows are set on the adding machine for this purpose.
How to check the he alth of the adding machine
In order for the device to work properly, it must be regularly checked for correct calculations. How to check the operation of the Felix adding machine, the instructions were given by the manufacturer himself - the Kursk plant "Schetmash" in the instruction manual. It is shown below.
- Put the carriage in the extreme left position, and dial 123456789 from left to right with the levers on the drum, and do 9full turns clockwise. The result window should display the number 1111111101;
- Do 9 more turns. The number 2222222202 should appear in the result window.
In order for the unit to remain in good condition for as long as possible and have a presentable appearance, it must be regularly lubricated and wiped with a soft cloth. Store the device in a warm and dry place in a cardboard or wooden box. Protect from dust and moisture.
Mechanical adding machine "Felix" is not used today. It is too long and difficult to make calculations on it, given that simple and lightweight electronic calculators are cheap or built into other types of equipment (watches, phones). But, as a rare item, it is highly valued by collectors. If in Soviet times it cost 11-15 rubles, today they give several thousand and even tens of thousands of rubles for it. Since there are fewer and fewer, the price of it will only increase.
