Rice. 148. Making a blocking capacitor, a - collected sheets of foil and paper; below is a view of the relative position of the foil sheets; b - the ends of the foil sheets are bent outward;

with – holder made of sheet brass for clamping the ends of the foil; d - finished capacitor

3. TABLES FOR CONVERSION OF MEASURES OF DIFFERENT SYSTEMS

As we said earlier, in our presentation we tried to adhere to the metric system of measures now adopted by us. However, in those cases where the old Russian or English measures have not yet gone out of use in the sale of certain types of materials, we have provided data on these measures as well.

In case any of the readers still have to translate metric measures in Russian or, with a more complete establishment of the metric system in our country, the old measures placed in the text - in metric, we give the following tables, covering all the data found in the previous chapters.

Comparison of metric and Russian measures

A. Comparison of metric and Russian measures.

In 1795, the Law on New Measures and Weights was passed in France, which established a single unit of length - meter, equal to ten millionths of a quarter of the arc of the meridian passing through Paris. Hence the name of the system - metric.

A platinum rod one meter long and of a very strange shape was chosen as the standard of the meter. Now the size of all rulers, one meter long, had to correspond to this standard.

Units installed:

- liter as a measure of the capacity of liquid and granular bodies, equal to 1000 cubic meters. centimeters and containing 1 kg of water (at 4 ° heat Celsius),

- gram as a unit of weight (weight clean water at a temperature of 4 degrees Celsius in the volume of a cube with an edge of 0.01 m),

- ar as a unit of area (the area of ​​a square with a side of 10 m),

- second as a unit of time (1/86400 of a mean solar day).

Later, the basic unit of mass became kilogram. The prototype of this unit was a platinum weight, which was placed under glass flasks and the air was pumped out - so that dust would not get in and the weight would not increase!

The prototypes of the meter and kilogram are still kept in the National Archives of France and are called "Meter Archive" and "Kilogram Archive" respectively.

There were different measures before, but an important advantage of the Metric system of measures was its decimality, since submultiple and multiple units, according to the accepted rules, were formed in accordance with the decimal count using decimal factors, which correspond to the prefixes deci, - centi, - milli, - deca, - hecto- and kilo-.

Currently, the metric system of measures is adopted in Russia and in most countries of the world. But there are other systems as well. For example, the English system of measures, in which the foot, pound and second are taken as the main units.

It is interesting that in all countries there are familiar packaging for different foods and drinks. In Russia, for example, milk and juices are usually packaged in liter bags. And large glass jars - entirely three-liter!

Remember: on professional drawings, the dimensions (dimensions) of products are signed in millimeters. Even if these are very large products, like cars!

Volkswagen Cady.

Citroen Berlingo.

Ferrari 360.

The large number and fragmentation of the measures applied hampered trade, economic and cultural ties between countries and caused confusion and abuse within individual states. The development of industrial production, the expansion of economic ties, the development of trade and exchange led to the idea of ​​creating a single system of measures common to all countries of the world.

The main provisions in the search for a new system were the following:

· natural origin of measures (new units of measures should be taken from nature);

the certainty of the measures;

independence of measures from time and accidents;

immutability and constancy of measures;

recoverability in case of loss;

commonality of the system of measures;

· convenience of interrelation of units of measures in the given system;

Decimal principle of ratios of measures to each other.

A system of measures that meets all of the above requirements was proposed by the Paris Academy of Sciences, which recommended that the basic unit be adopted as a meter, equal to one forty millionth of the arc of the earth's meridian passing through Paris. On March 26, 1791, the Constituent Assembly of France approved the proposal of the Paris Academy of Sciences, and in 1799 the work on the experimental determination of length and mass ended with the transfer of their platinum prototypes to the Archives of France for storage.

In accordance with this system, a meter was taken as a unit of length, a square meter as a unit of area, a cubic meter (ster) as a unit of volume, a kilogram as a unit of mass, equal to the mass of pure water of one cubic decimeter at a temperature of 4 0 C. The surface measure was approved ar ( from the word "aros" - to plow), equal to a square with a side of 10 m, and as a measure of volume for liquid and loose bodies - a liter, equal to the volume of a liquid of one cubic decimeter. All other units were established using a factor of 10, and their name was formed by adding prefixes (ancient Greek and Latin numerals) to the main units.

Metric system measure was originally conceived as an international one. Its units did not coincide with any national ones, and the names of units and prefixes were formed from "dead" languages. The law adopted by Napoleon on December 10, 1799 in Article 4 stated: “A medal will be made to convey to the memory of posterity the time when the system of measures was brought to perfection, and the operation that served as its basis. The inscription on the front side of the medal will be: "For all times, for all peoples." The medal itself was never issued, other, more advanced systems of measures appeared, and history has preserved the motto of the medal.

Despite its obvious advantage, the metric system of measures was introduced with great difficulty. Even in France itself, where the feudal lords had the right to use their own measures, the metric system was finally introduced only in 1840.

On May 20, 1875, at the suggestion of the St. Petersburg Academy of Sciences, a diplomatic conference was convened, at which 17 states, including Russia, signed the Meter Convention, which was later joined by 41 more countries of the world. In the same year, the International Organization of Weights and Measures (IOM) and the International Bureau of Measures and Weights (BIPM) were created, located in the French city of Sevres. In 1889, the standards of the unit of mass under the numbers 12 and 26 and the standards of the unit of length under the numbers 11 and 28 were transferred to Russia for storage.

The metric system, as the only one, was finally introduced in Russia in 1927. In a country where literacy was very low, and the variety of measures and their names, due to the vastness of the territory, is huge, the introduction of this system involved widespread propaganda and education. So in the "Guide to the study of the metric system of measures and weights" of the education service of the Omsk Railway from 1924, it says: "Any literate person must, first of all, be able to read, write and count. According to the instructions of the NKPS Training Department for poorly trained agents, the course program should include .... the history of the origin of the metric system and practical exercises, in order to give students the skill to use the metric system. There are currently…. units that are connected to each other without any system, and some, for example, arshins and feet, have no connection. And so, we have 27 used units of measurement of various names (approved for a given period in the Omsk region - my explanations) and all of them are very inconveniently connected with each other, or often have no connection at all. In addition, it is not so easy to keep them all in memory, and then any arithmetic operations on named numbers expressed in these units are very difficult and require a lot of attention and a significant investment of time. When did this new system, all civilized states have switched to it, with the exception of England, due to the extreme conservatism of its population and the North American United States.

Almost a century has passed, and Great Britain and the USA, along with the metric system, which is used mainly in science, still use their national systems of measures, which creates confusion and inconvenience, first of all, in the countries themselves. So, for example, a measure of grain - a bushel - currently has 56 different values. On January 1, 2000, the government of England obliged the citizens of the country to use the metric system, threatening "refuseniks" with fines. However, “despite the statutory mandate, about one third of the sixty thousand stores in the UK have not converted to the metric system. Adaptation to the continental system has been going on since 1969, when pounds, shillings and pesses were first transferred to the decimal system.

At present, metrology as a science, having passed its descriptive period, is developing dynamically. The expansion of international relations in the field of science, trade and production has led to the strengthening of the role of Interstate organizations in metrology. The International Organization of Legal Metrology (OIML) was established in 1955 and unites 83 states. Until now, the oldest and most representative international metrological organization, MOMV, does not stop its work. In 1988, the convention on the formation of EUROMET, a pan-European metrological organization, was signed.

Metric, a decimal system of measures, a set of units of physical quantities, which is based on a unit of length - meter. Initially, the Metric system of measures, in addition to the meter, included units: areas - square meter, volume - cubic meter and mass - kilogram (mass of 1 dm 3 of water at 4 ° C), as well as liter(for capacity), ar(for land area) and ton(1000 kg). An important distinguishing feature of the metric system of measures was the method of formation multiple units and submultiple units, which are in decimal ratios; prefixes were adopted to form the names of derived units: kilo, hecto, soundboard, deci, centi and Milli.

The metric system of measures was developed in France during the French Revolution. At the suggestion of a commission of major French scientists (J. Borda, J. Condorcet, P. Laplace, G. Monge, and others), the unit of length - meter - was taken as a ten-millionth part of 1/4 of the length of the Paris geographic meridian. This decision was due to the desire to base the metric system of measures on an easily reproducible "natural" unit of length, associated with some practically unchanged object of nature. The decree introducing the metric system of measures in France was adopted on April 7, 1795. In 1799, a platinum prototype of the meter was made and approved. The sizes, names and definitions of other units of the Metric system of measures were chosen so that it was not of a national character and could be accepted by all countries. The metric system of measures acquired a truly international character in 1875, when 17 countries, including Russia, signed Metric convention to ensure international unity and improve the metric system. The metric system of measures was approved for use in Russia (optionally) by the law of June 4, 1899, the draft of which was developed by D. I. Mendeleev, and introduced as a mandatory decree of the Council of People's Commissars of the RSFSR of September 14, 1918, and for the USSR - by a decree Council of People's Commissars of the USSR of July 21, 1925.

On the basis of the metric system of measures, a number of private measures arose, covering only certain sections of physics or branches of technology, systems of units and individual off-system units. The development of science and technology, as well as international relations, led to the creation on the basis of the metric system of measures of a single system of units covering all areas of measurement - International system of units(SI), which is already accepted as mandatory or preferred by many countries.