1776 – The signing of the United States Declaration of Independence took place.
The Declaration of Independence is the statement adopted by the Second Continental Congress meeting at Philadelphia, Pennsylvania on July 4, 1776, which announced that the thirteen American colonies, then at war with the Kingdom of Great Britain, regarded themselves as thirteen newly independent sovereign states, and no longer under British rule. Instead they formed a new nation—the United States of America. John Adams was a leader in pushing for independence, which was passed on July 2 with no opposing vote cast. A committee of five had already drafted the formal declaration, to be ready when Congress voted on independence. The term “Declaration of Independence” is not used in the document itself.
John Adams persuaded the committee to select Thomas Jefferson to compose the original draft of the document, which Congress would edit to produce the final version. The Declaration was ultimately a formal explanation of why Congress had voted on July 2 to declare independence from Great Britain, more than a year after the outbreak of the American Revolutionary War. The next day, July 3, John Adams wrote to his wife Abigail: “The Second Day of July 1776, will be the most memorable Epocha, in the History of America.” But the national birthday, Independence Day, is celebrated on July 4, the date that the Declaration of Independence was signed.
After ratifying the text on July 4, Congress issued the Declaration of Independence in several forms. It was initially published as the printed Dunlap broadside that was widely distributed and read to the public. The source copy used for this printing has been lost, and may have been a copy in Thomas Jefferson’s hand. Jefferson’s original draft, complete with changes made by John Adams and Benjamin Franklin, and Jefferson’s notes of changes made by Congress, are preserved at the Library of Congress. The best known version of the Declaration, a signed copy that is popularly regarded as the official document, is displayed at the National Archives in Washington, D.C. This engrossed copy was ordered by Congress on July 19, and signed primarily on August 2.
1790 – The first United States Census is conducted.
Censuses had been taken prior to the Constitution’s ratification; in the early 17th century, a census was taken in Virginia, and people were counted in nearly all of the British colonies that became the United States.
Throughout the years, the country’s needs and interests became more complex. This meant that statistics were needed to help people understand what was happening and have a basis for planning. The content of the decennial census changed accordingly. In 1810, the first inquiry on manufactures, quantity and value of products occurred; in 1840, inquiries on fisheries were added; and in 1850, the census included inquiries on social issues, such as taxation, churches, pauperism, and crime. The censuses also spread geographically, to new states and territories added to the Union, as well as to other areas under U.S. sovereignty or jurisdiction. There were so many more inquiries of all kinds in the census of 1880 that almost a full decade was needed to publish all the results. In response to this, the census was mechanized in 1890, with tabulating machines made by Herman Hollerith. This reduced the processing time to two and a half years.
1870 – Tower Subway, the world’s first underground tube railway, opens in London, England, United Kingdom.
The Tower Subway is a tunnel beneath the River Thames in central London, between Tower Hill on the north side of the river and Vine Lane (off Tooley Street) on the south. In 1869 a 1,340-foot (410 m) circular tunnel was dug through the London clay using a wrought iron shield, a method that had been patented in 1864 by Peter W. Barlow. A 2 ft 6 in (762 mm) narrow gauge railway was laid in the tunnel and from August 1870 a cable-hauled wooden carriage conveyed passengers from one end to the other. This was uneconomic and the company went bankrupt by the end of the year. The tunnel was converted to pedestrian use and one million people a year crossed under the river, paying a toll of 1⁄2d. The opening of the toll-free Tower Bridge in 1894 caused a drop in income and the tunnel closed in 1898, after being sold to the London Hydraulic Power Company. Today the tunnel is used for water mains.
The same method of construction was used in 1890 to dig the tunnels of the City and South London Railway, the first of London’s “Tube” railways.
1835 – Elisha Gray, American businessman, co-founded Western Electric, is born.
Elisha Gray was an American electrical engineer who co-founded the Western Electric Manufacturing Company. Gray is best known for his development of a telephone prototype in 1876 in Highland Park, Illinois. Some recent authors have argued that Gray should be considered the true inventor of the telephone because Alexander Graham Bell allegedly stole the idea of the liquid transmitter from him, although Bell had been using liquid transmitters in his telephone experiments for more than two years previously. Bell’s telephone patent was held up in numerous court decisions.
Gray is also considered to be the father of the modern music synthesizer, and was granted over 70 patents for his inventions. He was one of the founders of Graybar, purchasing a controlling interest in the company shortly after its inception.
1932 – The positron (antiparticle of the electron) is discovered by Carl D. Anderson.
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has an electric charge of +1 e, a spin of 1/2, and has the same mass as an electron. When a low-energy positron collides with a low-energy electron, annihilation occurs, resulting in the production of two or more gamma ray photons (see electron–positron annihilation).
Positrons may be generated by positron emission radioactive decay (through weak interactions), or by pair production from a sufficiently energetic photon which is interacting with an atom in a material.
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