HE is the man behind the Time Ball and the One O’Clock gun, but few know the name of the man who fashioned two of Scotland’s most famous markers of time.

The life and works of Charles Piazzi Smyth, a colourful Victorian scientist, astronomer and Egyptologist is to be celebrated in a new exhibition in Edinburgh, the city on which he left a mark, but where he is, experts say, largely forgotten.

Smyth, born in Italy in 1819, 200 years ago, he was appointed the Astronomer Royal for Scotland in 1845 at the age of 26, and moved to Calton Hill.

He was the man behind the Time Ball, the sphere which drops from the top of the Nelson Monument every day at one in the afternoon, as a signal to the ships docked in Leith harbour.

Smyth instigated that simple but signal in 1852, and nine years later, in 1861, added a loud noise as a further sign to ships: the One O’Clock Gun, placed on Edinburgh Castle.

This additional sign was enabled by a cable, which ran from Calton Hill to another on Castle Rock.

Both signals are active in modern times, although the cable is no longer in place.

The new exhibition, at the Nelson Monument, is aiming to re-establish Piazzi Smith as a notable figure in Edinburgh history.

In a year-long series of events, the free show presents his photography, paintings and drawings, alongside a new short film and interviews, in what will be the first major exhibition in Edinburgh dedicated to the astronomer.

The current Regius Professor of Astronomy at the University of Edinburgh, Professor Andy Lawrence said: “Piazzi Smyth and his wife Jessie [Jessica Duncan] are great Edinburgh characters but are forgotten in the city where they worked.

“Astronomers tour the world to observatories because of Charles’ work. His scientific work underpins much of our work today.”

He added: “As we launch the exhibition, we are also beginning a grand Time Gun Public Experiment.

“As a first step, we just want to find out who can hear the One O’ Clock Gun.”

Professor Lawrence said that on any day between 8 April and 14 April, he is asking visitors to the city, and its citizens, to listen out for the gun and let the Royal Observatory know on social media.

He added: “Later in the year we will get more ambitious and time the delay all over town.”

The name of Piazzi Smith recently crept into the news, when there was some controversy over an exhibit, a stone from the Great Pyramid, was announced as part of the new Egyptian exhibition at the National Museum of Scotland.

In 1865 Piazzi Smyth had initiated a programme of research including the first largely accurate survey of the Great Pyramid, and in doing so, he had the official permission of the Viceroy of Egypt and the assistance of the Egyptian Antiquities Service.

The stone was brought to the UK by Waynman Dixon in 1872 and transported to Charles Piazzi Smyth in Edinburgh: the NMS believes it is secure in its rights to the artefact.

Councillor Donald Wilson, culture convener for the City of Edinburgh Council, said: “This fascinating exhibition will really shine a light on one of Scotland’s most important astronomers.

“Throughout his 40 years as Astronomer Royal for Scotland, Piazzi Smyth did much of his work from Calton Hill and with his invention of the Time Ball service, it is extremely fitting to house this wonderful exhibition in the Nelson Monument.

“For hundreds of years, Calton Hill has been a cherished place for star gazers and has association with many prominent individuals from Scotland’s history such as David Hume, Robert Burns and William Henry Playfair.

“Now it is time to spread the word about Edinburgh’s forgotten astronomer, Charles Piazzi Smyth and his place in Scottish history.”

When Piazzi Smyth was appointed Astronomer Royal for Scotland at the Calton Hill Observatory in Edinburgh, and also Professor of Astronomy in the University of Edinburgh.

However, Piazzi Smyth found that the polluted skies obscured the stars.

Along with his wife he decided to take state of the art telescopes to Tenerife in 1856, climbing to altitudes of over 10,000ft.

It is through this work he can be said to have pioneered today’s practice of positioning telescopes on mountain tops to obtain better observations.

As Astronomer Royal for Scotland he spent much of his time and did much of his work from the City Observatory on Calton Hill, which recently reopened to the public after 100 years.

Piazzi Smyth’s measurements of the Great Pyramid at Giza won him a medal, but his beliefs around pyramids caused him to resign from the Royal Society and the Royal Society of Scotland after arguments about science and religion.

The exhibition is a partnership between Royal Observatory Edinburgh, Museums & Galleries Edinburgh, University of Edinburgh and the Astronomical Society of Edinburgh.

Piazzi Smyth was born in Italy in 1819.

At the age of 16 he went to the Cape Observatory, South Africa to begin a career in astronomy.

In 1855 he married Jessie Duncan and in 1865 went to Egypt to measure the Great Pyramid of Giza.

Piazzi Smith was awarded a prize for measurement on the pyramid, but had arguments with other scientists about the conclusions on the pyramid work, and he resigned from Royal Society in 1874.

In 1888 he resigned from Astronomer Royal for Scotland, in part due to concerns about funding.

He retired to Ripon, Yorkshire, and Jessie died 1896.

Piazzi Smyth died 1900: both are buried at Ripon.