Sir Robert Watson-Watt

Each major claim carries one of three labels. established means supported by primary records, official bodies or several independent reliable sources. shared means the core fact is sound but sources disagree on details, dates or interpretation. traditional means widely repeated but not traceable to a primary or independent source.

Watson-Watt's work is documented by the National Physical Laboratory, government records and his own memoirs. Popular accounts tend to overstate his role as a lone inventor, and repeat his claimed descent from James Watt without evidence. Sources differ slightly on some figures, such as the number of Chain Home stations at the start of the war.

From Brechin to the weather service

established Robert Watson Watt, as his name was then written, was born in Brechin on 13 April 1892. He went to Brechin High School and then University College, Dundee, graduating in engineering in 1912. He joined the Meteorological Office during the First World War and worked on detecting the radio signals given off by lightning, so that pilots could be warned of thunderstorms. In 1924 he moved to the Radio Research Station at Slough, which became part of the National Physical Laboratory.

shared Sources give 1915 or 1916 for his move to the Meteorological Office.

From death ray to detection

established In January 1935 Harry Wimperis of the Air Ministry asked Watson-Watt whether a radio "death ray" could destroy aircraft. Watson-Watt and his assistant Arnold Wilkins worked out that it could not, but that aircraft would reflect radio waves strongly enough to be detected. Watson-Watt set this out in a secret memo dated 12 February 1935.

The Daventry Experiment

established On 26 February 1935, in a field near Daventry, Watson-Watt and Wilkins set up a receiver about six miles from the BBC's shortwave transmitter. A Handley Page Heyford bomber flew along the beam, and the echo showed clearly on their screen. Only three people saw it: Watson-Watt, Wilkins and A. P. Rowe of the Air Ministry. A plaque now marks the site.

Chain Home

established Research moved to Orford Ness in 1935 and then to Bawdsey Manor in Suffolk, where Watson-Watt became superintendent in 1936. The first Chain Home stations began round-the-clock watch in 1938, and a chain of stations along England's east and south coasts was in place before the war began. In the Battle of Britain in 1940, Chain Home gave the RAF early warning of German raids, allowing it to send its limited fighter force where it was needed. More than 50 stations were built by the end of the war.

shared Sources give between 19 and 20 Chain Home stations operating at the start of the war.

Father of radar?

shared Watson-Watt is often called the father of radar. The title reflects his leadership of the team that turned radio detection into a working national warning system. It does not mean he worked alone: Wilkins made the key calculations, and many engineers built Chain Home.

Honours and later life

established Watson-Watt was elected a Fellow of the Royal Society in 1941 and knighted in 1942. In 1952 the government awarded him £50,000 for his work. He published his memoir, Three Steps to Victory, in the 1950s. He later worked in Canada and the United States, and married for the third time in 1966, to Dame Katherine Trefusis Forbes. He died in Inverness on 5 December 1973 and is buried at Pitlochry. A statue of him was unveiled in Brechin in 2014.

The speed trap

established In 1956 Watson-Watt was stopped for speeding in Canada by a police officer using a radar gun. He later wrote a comic poem, "A Rough Justice", about being caught by his own invention.

traditional He is said to have exclaimed that if he had known what they would do with it, he would never have invented it. The remark is widely quoted, but its exact wording is not well documented.

James Watt?

shared Watson-Watt claimed descent from James Watt, the steam engineer, and some popular accounts repeat this as fact. No evidence of a family relationship has been found.

• Watson-Watt began by trying to detect thunderstorms by their radio signals.
• Radar grew out of a question about whether a "death ray" was possible.
• Only three people witnessed the Daventry Experiment in 1935.
• The test aircraft was a Handley Page Heyford bomber.
• A statue of him stands in his home town of Brechin.
• He was awarded £50,000 by the government in 1952.
• He was caught by a radar speed trap in Canada in 1956.
• He wrote a comic poem about it called "A Rough Justice".

• Do not call Watson-Watt the sole inventor of radar.
• Do not say he was descended from James Watt; no link has been found.
• Do not leave out Arnold Wilkins.
• Do not say radar alone won the Battle of Britain.