First Commercial Radio Broadcast Aired...1920..Wikipedia

Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space. Information is carried by systematically changing (modulating) some property of the radiated waves, such as amplitude, frequency, phase, or pulse width. When radio waves pass an electrical conductor, the oscillating fields induce an alternating current in the conductor. This can be detected and transformed into sound or other signals that carry information. 


 Classic Radio 

Tesla demonstrating wireless transmissions during his high frequency and potential lecture of 1891. After continued research, Tesla presented the fundamentals of radio in 1893.

In 1896, Marconi was awarded British patent 12039, Improvements in transmitting electrical impulses 

and signals and in apparatus there-for, for radio. In 1897, he established a radio station on the Isle of Wight, England. Marconi opened his "wireless" factory in Hall Street, Chelmsford, England in 1898, employing around 50 people. Shortly after the 1900s, Marconi held the patent rights for radio.

20th century

Telephone Herald in Budapest, Hungary(1901).

The next advancement was the vacuum tube detector, invented by Westinghouse engineers. On Christmas Eve, 1906, Reginald Fessenden used a synchronous rotary-spark transmitter for the first 

radio program broadcast, from Ocean Bluff-Brant Rock, Massachusetts. Ships at sea heard a broadcast that included Fessenden playing O Holy Night on the violin and reading a passage from the Bible. This was, for all intents and purposes, the first transmission of what is now known as amplitude modulation or AM radio. The first radio news program was broadcast August 31, 1920 by station 8MK in Detroit, Michigan, which survives today as all-news format station WWJ under ownership of the CBS network.

UK:

in contrast, related developments in the United Kingdom saw the British High Court uphold Marconi's British Patent 7,777 that was issued on April 26, 1900. This British patent held by Marconi disclosed a four-circuit system, which was strikingly similar to a four-circuit system disclosed in U.S. patent #645,576 that was issued earlier to Tesla on March 20, 1900. On the matter of invention, it is held that Marconi knowingly and unknowingly used the scientific and experimental work of many others who were devising their own radio tuning apparatus' around the same time, such as the work of American electrical engineer John Stone Stone who was issued several U.S. patents between 1904 and 1908. However, what made Marconi more successful than any other was his ability to commercialize radio and its associated equipment into a global business.^]

The Difference Between Memorial Day and Veterans Day

By: Helen Polaski

The difference between Memorial Day and Veterans Day may be blurry to some people, but to the people who have lost loved ones to war or who are currently in the United States Armed Services, the difference is crystal clear. Because Americans observe both holidays, many believe they serve the same purpose. In reality, there is a tremendous difference, with one holiday recognizing those who fought for America and the other remembering those who lost their lives.

Origins of Memorial Day and Veterans Day
Though both days of observance have been set aside to honor members of the United States Armed Forces, each of the two days was singled out for completely different reasons. One of them falls on an important date in world history, while the other date was set by an act of Congress.

Memorial Day is a day of remembrance. Memorial Day is always observed on the last Monday in the month of May. It is on this day that we remember those who have given their lives in defense of the United States. This includes all those who have gone before us, and who gave up their lives in battle or in service to our country for our freedom. These men and women have earned a day of distinction.

Memorial Day began in the aftermath of the Civil War. Originally known as Decoration Day, this day was set aside for war widows to visit their husbands' graves. Many women brought flowers and wreaths to thank their lost husbands for helping to keep America as one nation. In 1882, the day began to be observed nationally as a day of remembrance for all fallen soldiers. After World War I, Memorial Day was observed on May 30. The Uniform Holidays Act, which went into effect in 1971, moved Memorial Day to the last Monday of May as a way to encourage business owners to give employees the day off.

Veterans Day is a day of remembrance following the ceasefire of World War I. While the war did not officially end until the Treaty of Versailles was signed on June 28, 1919, fighting ceased seven months earlier when an armistice was agreed upon between Germany and the Allied Nations. Because the cessation of fire went into effect on the 11^th hour of the 11^th day of the 11^th month, President Woodrow Wilson proclaimed November 11 Armistice Day.

Originally intended as a day to honor World War I veterans, Armistice Day was expanded in many parts of America to include World War II veterans during the 1950s. President Dwight D. Eisenhower, himself a World War II veteran, made the name change official in 1954.

As part of the Uniform Holiday Act, Veterans Day was moved to the fourth Monday in October in 1971 and designated an official federal holiday. By 1978, the date moved back to November 11. Schools and government facilities typically close on Veterans Day, but most businesses remain open.  Some European countries still observe Armistice Day as a day to remember World War I.

It is understandable how the two days of observance can become misinterpreted as both observances are heralded by parades, picnics and community gatherings. The best way to distinguish the two days of observance in your mind is to remember that Memorial Day, or the day to honor those who have fallen or gone before us, is observed in the spring, as it comes before Veterans Day, which is observed on November 11 to honor those who are still with us.

First Traffic Light..1914

Inventing history:
Garrett Morgan and the traffic signal

In early 1922, African-American inventor Garrett Augustus Morgan designed a cross-shaped traffic signal, for which he submitted a patent application on February 27 of that year. The patent — which was not even among the first 50 traffic signal patents issued in the United States — was granted on November 20, 1923. For whatever reason, numerous writers and public figures have credited Morgan with inventing any or all of the following:

• world's first traffic signal
• first traffic signal to earn a patent
• first automatic traffic signal
• first traffic signal with a third "all-directional stop" phase
• first signal with a yellow light phase
• the basis for modern traffic signal systems

None of these claims are even remotely true, as rest of this page shows.

Myth: Garrett Morgan invented the first traffic signal

Some notable early signals, prior to Morgan's 1922 invention

London, 1868

The first known signal device for regulating street traffic was installed in 1868 in London, at the intersection of George and Bridge Streets near the Houses of Parliament. Designed by railroad signal engineer JP Knight, it had two semaphore arms which, when extended horizontally, meant "stop"; and when drooped at a 45-degree angle, meant "caution." At night, red and green gas lights accompanied the "stop" and "caution" positions (Sessions 1971;Mueller 1970).

By the signal "caution", all persons in charge of vehicles and horses are warned to pass over the crossing with care and due regard to the safety of foot passengers. The signal "stop" will only be displayed when it is necessary that vehicles and horses shall be actually stopped on each side of the crossing, to allow the passage of persons on foot; notice being thus given to all persons in charge of vehicles and horses to stop clear of the crossing.

Proclamation of Richard Mayne, London Police Commissioner, in 1868; quoted in Mueller 1970

Salt Lake City, about 1912

A contender for "inventor of the first electric traffic light" is Lester Wire of Salt Lake City (Sessions 1971).

Mr. Wire, who died in 1958, was a Salt Lake police officer who invented the first electric traffic light in 1912.... The first hand-made model was a wooden box with a slanted roof so rain and snow would fall off. The lights were colored with red and green dye and shone through circular openings. The box was mounted on a pole, and the wires were attached to the overhead trolley and light wires. It was operated by a policeman. In ensuing years, Mr. Wire improved upon the first model.

"Peak Named for Inventor," Deseret News (Salt Lake City), February 9, 1967

Cleveland, Ohio, 1914

On August 5, 1914, several years before Garrett Morgan invented his T-shaped semaphore-type signal, the American Traffic Signal Company installed red and green traffic lights at each corner of the intersection of 105th Street and Euclid Avenue in Cleveland (see this 1914 Motorist article documenting the debut of the lights).

The installation was patterned after the design of Cleveland inventor James Hoge (Sessions 1971; Mueller 1970), whose U.S. patent #1,251,666 describes a system of electrically powered stop-go indicators, each mounted on a corner post. In Hoge's design, the signals are wired to a manually operated switch housed inside a control booth, and are electrically interlocked in such a way as to make conflicting signals impossible. Also described in the patent is a system to allow communication between the signal controller and the police and fire departments. The Cleveland installation incorporated all of the above elements in some form or other, plus a bell to warn the drivers of color changes.

from Hoge's patent #1,251,666

William Potts' 4-way, red-yellow-green signals, Detroit, 1920

In October and December of 1920, a Detroit policeman named William Potts constructed several red-yellow-green light signal systems. Some lights were mounted atop "traffic towers" manned by policemen; others were overhead suspension lamps remarkably similar in form to a modern traffic light. The 4-direction traffic lamp pictured below is of the latter type, and is on display at the Henry Ford Museum in Dearborn, Michigan.

A 1920 vintage Potts signal, at the Henry Ford Museum.

William Potts

An entry in the museum's artifact database describes the item:

The world's first three-color, four-direction, elec. traffic lamp, was installed at the intersection of Woodward Ave. and Fort Street, Detroit, Michigan in October, 1920. It was designed by Superintendent (then inspector) William L. Potts of the Signal Bureau, Detroit Police Department. Basic design remains practically unchanged today. The signal remained in use until 1924 and became a part of the world's first synchronized signal system. This system extended from Jefferson to Adams on Woodward Avenue and was controlled manually from a tower at Woodward and Michigan.

museum archives, Henry Ford Museum & Greenfield Village (as of Jan 29 2003)

The meanings of the colored lights were essentially the same as today. Green meant "go"; red meant "stop"; and yellow (amber) meant "clear the intersection" (Mueller 1970). An analogous color scheme had been used by the railroads, where as early as 1899, the New York, New Haven and Hartford Railroad introduced a system wherein red, yellow, and green meant "stop", "caution", and "all clear" respectively (Brignano 1981).