Galileo in Venice

It was on the 25th August 1609 that Galileo demonstrated his telescope to the authorities of Venice.

From the top of St Mark’s Campanile, Galileo showed several officials from the Senate and the ruling Doge the power of his new instrument which was capable of 8x magnification.

Galileo had based his telescope design on that of similar instrument that he had heard about which was invented the previous year by a Dutch spectacle maker but was yet to be patented.


Image Credit: Wikipedia – Painting by Giuseppe Bertini 1858 – Galileo Galilei showing the Doge of Venice how to use the telescope

At the time, Venice was a major maritime port and its ships were under regular threat of attack from the Turks and Galileo demonstrated the telescope as a potential maritime instrument which could be used to spot distant ships on the lagoon before they could be seen with the naked eye thus providing an early warning of enemy attack.

The Venetian officials were impressed and Galileo was rewarded with a professorship at the University of Padua along with a pension of 1,000 Florin per year.

Later that year, Galileo pointed his telescope at the Moon discovering that it was not smooth as was the belief at the time but in fact had mountains and craters.

Some months later, in January 1610 and with an improved telescope with a magnification of 30x, Galileo went on to discover the moons of Jupiter. As he observed these over several nights he realised that they must be orbiting the great planet, this discovery led him to wonder if these moons orbited Jupiter then perhaps the Earth is not the centre of the Universe but in fact it orbits the Sun?

At the time, this was a radical idea that was was contrary to the teaching of the Church as at the time the Copernican model where the Earth was the centre of the Solar system was the accepted theory.

Galileo’s discovery landed him in big trouble with the Church over the following years and he was accused of heresy for the suggestion that the Earth moves around the Sun, he was, threatened with torture, made to confess that he was wrong and that the Earth was at the centre of the solar system.


Image Credit: Wikipedia: Painting by Cristiano Banti 1857 – Galileo facing the Roman Inquisition – in 1663 where he was found ‘gravely suspect of heresy’.

Galileo lived out his final years under house arrest near Florence until his death in 1642. He was posthumously pardoned by by the Vatican (Pope John Paul II) in 1992.

St Marks Campanile

The Bell tower at St Marks Basilica today, just under t 100 metres high. Where just over 400 years ago Galileo demonstrated his telescope. The bell tower was originally constructed in the 9th century and used as a watchtower, it was rebuilt in its current form in the early 1500s but collapsed in 1902 and was subsequently rebuilt to the same design in 1912.

View from St Marks Campanile

View from the top of the bell tower, looking across the lagoon to the sea.