In 1584 someone proposed a decimal system of units and money. Who was it?

Answer 1

Simon Stevin

Stevin wrote a small pamphlet called De Thiende ('the tenth'), first published in Dutch in 1586, and not exceeding seven pages in the French translation.

Decimal fractions had been employed for the extraction of square roots some five centuries before his time, but nobody established their daily use before Stevin. He felt that this innovation was so significant, that he declared the universal introduction of decimal coinage, measures and weights to be merely a question of time.

WAS HE RIGHT?

About 200 years were to elapse before his prediction became true as regards weights and measures.

In the late 18th century, Louis XVI of France charged a group of savants to develop a unified, natural and universal system of measurement to replace the disparate systems then in use. This group, which included such notables as Lavoisier, produced the metric system, which was then adopted by the revolutionary government of France.

DECIMAL CURRENCY

This started to happen rather sooner.

Russia was the first country to convert to a decimal currency. In 1710, Peter the Great set the ruble equal to 100 kopecks in a series of reforms to modernize Russia.

The United States introduced decimal currency with the dollar in 1792 (adopting only the currency aspects of a more comprehensive decimal system of measurements proposed by Thomas Jefferson).

In France, decimalisation of the coinage was accompanied by metrication of other measures, introducing the franc in 1803 to replace the Livre tournois, abolished during the Revolution.

France imposed decimalisation on a number of countries that it occupied during the Napoleonic period.

Later in the century, Canada converted to decimal coinage in 1859, and Sri Lanka (formerly Ceylon) in 1869.

India changed from the rupee, anna, pie system to decimal currency in 1957. Pakistan followed in 1961.

CONCLUSION:

There seems to have been an eerie inevitability about it as more and more countries converted to decimalisation. It shows what a visionary Stevin was to have grasped the potential of the system he devised and to foresee its appeal and the logic of adopting it,

AS REGARDS DECIMALISING TIME

Time, on the other hand, has not been metricated in everyday use: years, months, weeks, days, hours, minutes, and seconds, with non-decimal conversion factors, are used. The second and its submultiples, (e.g. microsecond), are used in scientific work, but the traditional units of time are more often used than decimal multiples of a second.

The original metric system was intended to be used with the units of time of the French Republican Calendar, but these fell into disuse along with the calendar.

THE FRENCH REPUBLICAN CALENDAR

The French Republican Calendar or French Revolutionary Calendar is a calendar proposed during the French Revolution, and used by the French government for about twelve years from late 1793.

It was designed by the politician and agronomist Charles Gilbert Romme, although it is usually attributed to Fabre d'Églantine, who invented the names of the months. The calendar was adopted by the Jacobin-controlled National Convention on 24 October 1793.

Years appear in writing as Roman numerals (usually), counted from the beginning of the 'Republican Era', 22 September 1792 (the day the French First Republic was proclaimed, one day after the Convention abolished the monarchy).

As a result, Roman Numeral I indicates the first year of the republic, that is, the year before the calendar actually came into use. The first day of each year included the autumnal equinox. There were twelve months, each divided into three ten-day weeks called décades. The five or six extra days needed to approximate the tropical year were placed after the months at the end of each year.

Each day was divided into ten hours, each hour into 100 decimal minutes and each decimal minute had 100 decimal seconds. Clocks were manufactured to display decimal time, but it did not catch on and was officially abandoned in 1795, although some cities continued to use decimal time as late as 1801.

A period of four years ending on a leap day was to be called a "Franciade".

THE MONTHS

The Republican calendar year began at the autumn equinox and had twelve months of 30 days each, which were given new names based on nature:

Autumn:
Vendémiaire (from Latin vindemia, "vintage") Starting Sept 22, 23 or 24
Brumaire (from French brume, "mist") Starting Oct 22, 23 or 24
Frimaire (From French frimas, "frost") Starting Nov 21, 22 or 23

Winter:
Nivôse (from Latin nivosus, "snowy") Starting Dec 21, 22 or 23
Pluviôse (from Latin pluviosus, "rainy") Starting Jan 20, 21 or 22
Ventôse (from Latin ventosus, "windy") Starting Feb 19, 20 or 21

Spring:
Germinal (from Latin germen, "seed") Starting Mar 20 or 21
Floréal (from Latin flos, "flower") Starting Apr 20 or 21
Prairial (from French prairie, "meadow") Starting May 20 or 21

Summer:
Messidor (from Latin messis, "harvest") Starting Jun 19 or 20
Thermidor (from Greek thermos, "hot") Starting Jul 19 or 20
Fructidor (from Latin fructus, "fruits") Starting Aug 18 or 19

In England, people against the Revolution mocked the calendar by calling the months: Wheezy, Sneezy and Freezy; Slippy, Drippy and Nippy; Showery, Flowery and Bowery; Wheaty, Heaty and Sweety

Answer 2

As early as 1584 Simon Stevenius had already proposed a decimal system of units and money in his book De Thiende. However, it was not until the French Revolution that the climate was conducive to creating a completely new system of units. In 1790 the French Academy of Science was commissioned by the National Assembly to design a new system of units for use throughout the world. They decided that this system should have the following attributes:

the system should consist of measuring units based on unvariable quantities in nature,
all units other than the base units should be derived from these base units,
multiples and submultiples of the units should be decimal.

Answer 3

That would be Simon Stevin, also known as Simon Stevenius. In 1584 or 1586 (sources vary), he published a pamphlet De Thiende ("The Tenth"), in which he proposed a decimal basis for units and currency. He was the first person to establish the daily use of decimal fractions, though his notation was quite awkward.

Answer 4

Simon Stevin (1548/49 – 1620) was a Flemish mathematician and engineer.


Stevin wrote a small pamphlet called De Thiende ('the tenth'), first published in Dutch in 1586, and not exceeding seven pages in the French translation.

Decimal fractions had been employed for the extraction of square roots some five centuries before his time, but nobody established their daily use before Stevin. He felt that this innovation was so significant, that he declared the universal introduction of decimal coinage, measures and weights to be merely a question of time.


I'm not sure if this is who you're looking for.

Answer 5

david K 93 beat me to it...

Answer 6

Now all we need to do is decimalise time :-)