The logarithmic ruler is the main counting device of the 20th century

In the age of computer technology, most calculations in the design of technology are fully automated, engineers can only enter through the user-friendly interface the required parameters.

XX century was called differently. It was atomic, and cosmic, and information. Aircraft designers improved planes, and they turned from clumsy biplanes into fast supersonic MiGs, Mirages and Phantoms. Giant aircraft carriers and submarines began to plow the seas and oceans at all latitudes. In Los Alamos (New Mexico), they tested an atomic bomb, and the first nuclear power plant started to provide energy in Obninsk near Moscow. The rockets fluttered ...

How did the atomic bomb count , missiles and jets?

Historical chronicles demonstrate the process of working on these achievements. Scientists and engineers in white coats, standing at the culmination and sitting at the tables that have been littered with drawings, produce the most complicated technical and scientific calculations on the arithmometers. Sometimes in the hands of Tupolev, Kurchatov or Teller, suddenly a thing unfamiliar to the modern young man - a logarithmic ruler. The photo of those whose youth took place in the post-war decades, up to the 80's, also recorded this simple article, which successfully replaced them with a calculator while studying at the institute or graduate school. Yes, and theses, too, was considered on her, on her own.

By what principle is the logarithmic ruler arranged?

The main principle of the work of this wooden object, neatly pasted with celluloid white scales, is based on the logarithmic calculus, as it follows from the name. More precisely, on the decimal logarithm. After all, everyone who taught higher mathematics knows that their sum is equal to the logarithm of the product, and, therefore, by correctly dividing into mobile parts, it is possible to achieve that multiplication (and hence division), squaring (and extracting the root) Will be a simple matter.

The rule of the logarithmic became popular as early as in the XIX century, when the main means for carrying out calculations were ordinary scores. This invention is a real find for then scientists and engineers. Not all of them figured out how to use this device at once. To learn all the wisdoms and to reveal its possibilities to the fullest, the fans of the new counting mechanism had to read special manuals, large enough. But it was worth it.

Rulers are different, even round

Nevertheless, the main advantage that the logarithmic ruler possesses is its simplicity, and consequently, its reliability. Compared to other methods of calculation (there were no calculators yet), operations were much faster. But there are moments that should not be forgotten. You can make calculations only with mantissa, that is, an integer (up to nine) and a fractional part of the number, with an accuracy of two (three who have very good eyesight) decimal places. The order of the numbers had to be kept in mind. There was one more drawback. The line is logarithmic, although small, but it is difficult to call it a pocket device - 30 centimeters all the same.

However, the dimensions did not become an obstacle to inquiring minds. For those who by their nature of activity should have a counting device always with them, a compact logarithmic line was invented. A circular scale with arrows gave it a resemblance to a watch, and some models of expensive chronometers kept it on its dial. Of course, the capabilities of this device and its accuracy were somewhat inferior to the corresponding parameters of the classic line, but it could always be carried in your pocket. Yes, and it looked more aesthetic!