A view of Venice's Grand Canal by Francesco Guardi (1712-1793) is valued at £1.5m-2m ($2.5m-3.4m) ahead of an auction at Christie's London.

The work, executed in black chalk and pen and ink, will headline the sale of Old Master & British Drawings & Watercolours on July 10.

It is believed to be a preparatory sketch for a full scale work and as such offers a revealing glimpse into the artist's work process.

Guardi was one of the last great painters of the Venetian school

Guardi's A View of the Rialto Bridge, Looking North set his auction record when it achieved £26.7m ($45.7m) in a sale at Sotheby's London in 2011.

Other lots in the sale include another view of the city by British painter JMW Turner (1775-1851).

Titled Venice: The New Moon - The Dogana from the Steps of the Hotel Europa (1840), the work is one of around 150 watercolours painted on his final visit.  

Turner regularly achieves significant sums at auction, with a painting titled Modern Rome - Campo Vaccino (formerly in the collection of the Rothschild family) selling for a record £29.7m ($45.1m) in 2010.

More recently, a watercolour view of the River Lune in Cumbria sold for £217,250 ($338,932) at Bonhams London in 2012.

You can check out our fine selection of art and photography memorabilia here.

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