By the mid 20th century, with the growing market for rare coins, the Sheldon system was adopted by the American Numismatic Association and most coin professionals in the North America.

In the mid 20th century, a " codec " was hardware that coded analog signals into Pulse-code modulation ( PCM ) and decoded them back.

Convergence theory is a broad term which includes a viewpoint popular among non-Marxist Chinese intellectuals of the mid 20th century.

RIT brand dye from mid 20th century Mexico, part of the permanent collection of the Museo del Objeto del Objeto.

The Fahrenheit scale was replaced by the Celsius scale in most countries during the mid to late 20th century.

Various " grammar frameworks " have been developed in theoretical linguistics since the mid 20th century, in particular under the influence of the idea of a " universal grammar " in the United States.

Greenwich Village, however, was known in the late 19th to mid 20th centuries as an artists ' haven, the bohemian capital, and the East Coast birthplace of the Beat movement.

* Index cards in a rolodex or old library card catalog, early and mid 20th century technologies for maintaining such lists

There have been strong developments for the kantele in Finland since the mid 20th century, starting with the efforts of modern players such as Martti Pokela in the 1950s and 1960s.

Since the mid 20th century, computers calculate the required functions instead.

The reconstruction is conjectural, as the gate was excavated by Layard in the mid 19th century, and reconstructed in the mid 20th century.

Note that this distinction was not always made, particularly before the development of the modern concept of phoneme in the mid 20th century.

Bla Bla Caja Mágica Tocadiscos record player box from the mid 20th century from the permanent collection of the Museo del Objeto del Objeto.

It has thus been the accent of those with power, money and influence since the early to mid 20th century, though it has more recently been criticised as a symbol of undeserved privilege.

Several 30-contact relays in " Connector " circuits in mid 20th century 1XB switch and 5XB switch telephone exchanges ; cover removed on one

Whorf's writings became the focus of empirical studies in psychology in the mid 20th century, and this strand of research often referred to the question as the Sapir-Whorf Hypothesis, or sometimes the Whorfian hypothesis.

The sandwich originated in several different Italian American communities in the Northeastern United States from the late 19th to mid 20th centuries.

The word was then intended to refer to what was sometimes known as pea soup fog, a familiar and serious problem in London from the 19th century to the mid 20th century.

By the mid 20th century, humans had achieved a mastery of technology sufficient to leave the atmosphere of the Earth for the first time and space exploration | explore space.

Technical changes in printing and film in the mid to late 20th century made the creation of trilogies more feasible, while the development of mass media and modern global distribution networks has made them more likely to be lucrative.

Originally suggested in the 19th century, the hypothesis enjoyed wide acceptance among linguists into the mid 20th century.

The book is illustrated with many photographs from the collection of Lady Sayer, a highly influential member of the Dartmoor Preservation Association during the mid 20th century.

The Three Stooges were an American vaudeville and comedy act of the early to mid – 20th century best known for their numerous short subject films.

After the fall of the Akkadian empire in the mid 21st century BC, the Assyrians who were the northern branch of the Akkadian people, colonised parts of the region between the 21st and mid 18th centuries BC and claimed the resources, notably silver.

The fort was partially destroyed by the Dutch in the mid 17th century, rebuilt, then destroyed again in 1776 by an earthquake.

The social system of " courtly love ", as gradually elaborated by the Provençal troubadours from the mid twelfth century, soon spread.

Assyria continued to exist as a geopolitical entity until the Arab-Islamic conquest in the mid 7th century AD, and Assyrian identity, personal names and both spoken and written evolutions of Mesopotamian Aramaic ( which still contain many Akkadian loan words ) have survived among the Assyrian people from ancient times to this day.

Local cuisine patterns had established by the mid 18th century.

These were followed by significant numbers of freed Africans in the War of 1812, Irish immigrants in the mid 19th century and Dutch immigrants after World War II.

For comparison, a Roman 1st BC century catapult using stones of 6. 55 kg fired with a kinetic energy of 16, 000 joules, while a mid 19th century 12 pound cannon firing projectiles of 4. 1 kg fired the projectile with a kinetic energy of 240, 000 joules.

By the Roman period brass was being deliberately produced from metallic copper and zinc minerals using the cementation process and variations on this method continued until the mid 19th century.

By the mid late 18th century developments in cheaper zinc distillation such as John-Jaques Dony's horizontal furnaces in Belgium and the reduction of tariffs on zinc as well as demand for corrosion resistant high zinc alloys increased the popularity of speltering and as a result cementation was largely abandoned by the mid 19th century.

Southern and mid-western states also passed numerous laws to protect Sunday during the mid to late 19th century.

If the Byzantines adopted the crescent and star as a symbol of their city after the events of the mid 4th century BC, one is forced to wonder why they waited several hundred years before putting the symbol on only some of their coins.

Until the mid 19th century most boats were of all natural materials ; primarily wood although reed, bark and animal skins were also used.

By the mid 19th century, many boats had been built with iron or steel frames but still planked in wood.

Boxing evolved from 16th and 18th century prizefights ( detailed further down the page ), largely in Great Britain, to the forerunner of modern boxing in the mid 19th century, again initially in Great Britain and later in the United States.

Since Daniel was a statesman during the Persian conquests, the Book of Daniel could have been written in a period when the Persians had their greatest influence on Aramaic, believed to be in the mid 6th century BC.

In the mid 3rd century, the Bastarnae were part of a Gothic-led grand coalition of lower Danube tribes which inflicted immense damage on the Balkan provinces of the Roman empire in a series of massive invasions.

During the mid 1st century AD, the Zarubintsy and Lukashevka cultures came to an end in their true form, possibly due to Sarmatian invasions and perturbations of central European trade due to Caesar's invasion of Gaul ( the ' heart ' of the La Tene culture ).

However, after a gap of 150 years, there is a final mention of Bastarnae in the mid 5th century.