IT'S HARD to believe a manufacturer could once get away with claiming that smoking could prevent sore throats, but that's exactly what Craven A cigarettes were supposed to do – according to adverts in the 1920s at least.

Similarly, at a time when middle class women were not expected to enjoy alcohol, Colman's was allowed to describe its Wincarnis tonic wine as a 'nerve restorative' – in other words a wholly acceptable way of drinking 'for medicinal purposes'. Guinness, of course, was famously 'good for you' and Oxo was 'for strength'.

A new exhibition has just opened at the Royal Cornwall Museum in Truro which provides an intriguing insight into the colourful world of early advertising – in particular the enamelled iron signs that were a common sight on buildings throughout Britain and the world from the 1880s to the 1950s.

Often attached to walls that were black and grimy from atmospheric pollution, the signs – kept polished by shopkeepers – gleamed like street jewellery, promising much with their clever wording and appealing imagery. Who wouldn't be tempted by some Fry's chocolate when presented with a picture of 'Fry's Five Boys' or discover a thirst when faced with a sign proclaiming Coca Cola as 'the ideal brain tonic'?

"Advertising today is governed by much stricter rules so it's fascinating to step back into an era when there was far less legislation around and see the kind of claims of manufacturers," said Georgia Butters, head of development and communications at the museum. "It's a rare chance to see how advertisers persuaded the public to buy everything from tobacco to boot polish before the age of TV advertising."

Collector Andrew Morley's 'So Near and Yet So Far' exhibition runs until April 1 at the Royal Cornwall Museum. Entry is free. For more details visit www.royalcornwall museum.org.uk or call 01872 272205.