What happened 1920 AD in United Kingdom

The first cycle of attacks and reprisals broke out in the summer of 1920. On 19 June a week of inter-sectarian rioting and sniping started in Derry, resulting in 18 deaths.

On 21 July 1920, partly in response to the killing of Smyth and partly because of competition over jobs due to the high unemployment rate, loyalists marched on the Harland and Wolff shipyards in Belfast and forced over 7,000 Catholic and left-wing Protestant workers from their jobs. Sectarian rioting broke out in response in Belfast and Derry, resulting in about 40 deaths and many Catholics and Protestants being expelled from their homes.

In 1904, John Ambrose Fleming invented the thermionic diode, the first kind of vacuum tube. This used a hot cathode that caused an electric current to flow in a vacuum. This idea was quickly applied to X-ray tubes, and hence heated-cathode X-ray tubes, called "Coolidge tubes", completely replaced the troublesome cold cathode tubes by about 1920.

On 22 August 1920, RIC Detective Swanzy was shot dead by Cork IRA men while leaving a church in Lisburn, County Antrim. Swanzy had been blamed by an inquest jury for the killing of Cork Mayor Tomás Mac Curtain.

The first cycle of attacks and reprisals broke out in the summer of 1920. On 19 June a week of inter-sectarian rioting and sniping started in Derry, resulting in 18 deaths.

On 21 July 1920, partly in response to the killing of Smyth and partly because of competition over jobs due to the high unemployment rate, loyalists marched on the Harland and Wolff shipyards in Belfast and forced over 7,000 Catholic and left-wing Protestant workers from their jobs. Sectarian rioting broke out in response in Belfast and Derry, resulting in about 40 deaths and many Catholics and Protestants being expelled from their homes.

In 1904, John Ambrose Fleming invented the thermionic diode, the first kind of vacuum tube. This used a hot cathode that caused an electric current to flow in a vacuum. This idea was quickly applied to X-ray tubes, and hence heated-cathode X-ray tubes, called "Coolidge tubes", completely replaced the troublesome cold cathode tubes by about 1920.

On 22 August 1920, RIC Detective Swanzy was shot dead by Cork IRA men while leaving a church in Lisburn, County Antrim. Swanzy had been blamed by an inquest jury for the killing of Cork Mayor Tomás Mac Curtain.