Previously, in the pre-computer era, people used a wide variety of auxiliary tools for counting and calculating. One such tool was an arithmometer. It accelerated the process of computing, but required certain knowledge and skills from the user.
What is
In the USSR, the calculator was the Felix arithmometer. This ingenious counting device was a real mechanical computer. He could perform four main actions: subtraction, addition, division and multiplication. Could work with numbers up to 9 registers long, and output the result up to 13-digit digits. That is, with numbers that not every modern calculator will cope with. However, working with him was difficult. He weighed a lot - 3.5 kg - and took up space on the table like an old computer with a CRT screen. I performed only the simplest operations of counting, but at the same time, in order to make calculations, I had to perform complex algorithms.
The Felix arithmometer was released from 1929 to 1971. Since this was the main computing tool used in many areas of the national economy, all Soviet schoolchildren underwent a compulsory training course on working with this device, just like modern schoolchildren are now taking computer lessons.
The machine can perform four simple counting operations: addition, subtraction, multiplication division. Some experienced specialists (accountants, design engineers) who were forced to work with him for a long time and even managed to calculate percentages and the root of the number on it. How to use the Felix arithmometer and make calculations is described below.
Addition
Addition is one of the simplest operations that can be performed. For example, you need to add the numbers 456 and 340. The calculation algorithm has the following form:
- Zero by rotating the rams (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 in the Felix arithmometer shown (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.
- Make a full turn of the handle clockwise.
- At the bottom of the carriage on the right in the results counter the number 456 should be highlighted. One will appear in the left windows of the carriage. If this does not happen, reset and enter the number as described above again.
- Dial the second number on the drum using the levers.
- Make one turn of the handle clockwise, and the result of addition will be displayed on the carriage.
Zeroing in subsequent calculations, if using the result of the previous one, is not necessary. Thus, you can add whole columns of numbers, introducing more and more numbers, and each time making a turn with the knob.
Subtraction
The algorithm of the Felix arithmometer when performing the subtraction operation is similar to the addition process, only the knob will need to be twisted in the opposite direction. Below are the steps you need to take to, for example, subtract 240 from 500.
- Set the handle to its original position, zero the numbers on the carriage.
- Enter the number 500 on the drum and rotate the crank one turn clockwise.
- Enter the number 240 on the drum and make a crank one revolution counterclockwise.
In the bottom right, in the answer window located on the carriage, the result of the subtraction should be displayed.
Multiplication
The following is the algorithm for multiplying 45 by 56.
- Set the arithmometer to its original position.
- Enter the number 56 on the drum.
- Slide the carriage one register (there is a lever at the bottom) and make 4 turns with the handle clockwise.
- Return the carriage to its original position and make 5 turns clockwise.
On the left, on the rev 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 arithmometer. Below is an algorithm of the steps that must be taken to divide 4455 into 355.
- Set the calculator to its original state.
- Move the carriage to the far right.
- Set the number 4455 using the leftmost drum levers. Start at 13 slots.
- Turn the knob clockwise. This number should be displayed in the results window on the left side.
- A unit is displayed in the revolutions window, zeroing it by turning the left lamb.
- Use the levers to set the number 355 opposite the dividend 4455. Simply put, set the number 355 using the leftmost drum levers.
- Move the carriage one register to the left and rotate the drum counterclockwise until the bell rings.
- Then make one revolution in a clockwise direction, after which you move the carriage to the left one more register and do a counterclockwise revolution before the call.
On the carriage in the left window you will see the quotient 12, and on the right side of the carriage the remainder 195. If you need to calculate to the hundredths, add two zeros to the number 4455 and continue the division, as described above. The added zeros are separated by a comma in the letter. On the arithmometer, arrows are installed for this purpose.
How to check the health of an arithmometer
In order for the device to work properly, it must be regularly checked for correct calculations. How to check the operation of the "Felix" arithmometer, the manufacturer gave the instruction - Kursk plant "Schetmash" in the instruction manual. It is given below.
- Put the carriage in the extreme left position, and dial 123456789 from left to right with the levers on the drum, and make 9 full turns clockwise. The number 1111111101 should be displayed in the results window;
- Do 9 more turns. The number 2222222202 should appear in the result window.
In order for the unit to remain in good condition 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 room in a cardboard or wooden box. Protect from dust and moisture.
The mechanical Felix arithmometer is not used today. It’s 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 thing, it is highly regarded by collectors. If in Soviet times it cost 11-15 rubles, today today they give for it several thousand and even tens of thousands of rubles. As they become less and less, the price of it will only increase.