New light shed on Monet's paintings of foggy London

Claude Monet painted his famous pictures of a foggy London skyline by direct observation rather than from memory, a scientific analysis of his paintings has found.

Monet dated the paintings to the time they were finished or sold, at which point he had already returned from London to his home at Giverny in Normandy, northern France.

This has led to speculation that he may have painted them from his impressions of London rather than from direct observation.

Scientists have analysed the position of the sun in Monet's works of art and used calculations of solar geometry to assess the time and place where the paintings were made. For the first time they have been able to determine to within a few feet the position where Monet was standing when he depicted a watery sun filtering through a foggy haze hanging over the Houses of Parliament.

Although it is known that Monet painted the Palace of Westminster from a room and terrace within St Thomas' Hospital, his precise location within the hospital was not known until now, said Jacob Baker, one of the authors of the study published in the Proceedings of the Royal Society A.

"We identify Monet's vantage point in St Thomas' Hospital to the second floor terrace of the Governors' Hall in the administrative block and to one of three locations along the terrace," Dr Baker said. "It is most likely that Monet positioned himself centrally along the terrace, since he would have been able to make use of the space within the central access area on to the terrace."

Monet made three trips to London in the autumn of 1899 and in the early months of 1900 and 1901 to paint his famous series of smoggy city landscapes. The series shows three views of London, two southward, from the Savoy Hotel, where he had a room, and one westward view of Parliament taken from St Thomas' Hospital on the south bank.

"It is not possible to say how many of the canvasses brought back from London were predominately finished and if Monet painted any of them entirely in Giverny," Dr Baker said. "Consequently, there is a great deal of doubt as to whether or not these paintings are authentic impressions of real observations taken from nature."

Dr Baker, working with a colleague, John Thomas, used the towers and spires of the Palace of Westminster to determine the precise position of the sun as it is depicted in the paintings, from which times and dates can be derived from a solar calendar. These were compared to the known dates that Monet was present in London and the timings matched Monet's letters of the period he was known to be in the capital - suggesting he had faithfully represented what he saw.

"Monet's letters state that he observed the sun on at least four separate occasions and these coincide with the main dates we have attributed to the paintings," Dr Baker said. "We know that it would have been quite difficult to see the sun due to cloud and pollution so Monet had to be very patient for the sun to appear."

The scientists now hope to use the colours in the paintings to analyse the type of pollution that caused the fogs over London.