WHENEVER I encounter the phrase ''the Grand Tour'' the image of an Italian detective, cigarette hanging from his lip, eyes screwed up against the smoke, tapping away on an old, black typewriter comes to mind.

You'll be no nearer making a connection if I tell you the year was 1973, the location, Venice. But more of my sordid adventures later.

The Grand Tour was a late seventeenth/early eighteenth century

phenomenon, when people set off across Europe on a journey discovery and, they hoped, enlightenment - the targets being Paris, Venice, and, particularly, Rome.

They sampled intellectual delights and frequently pleasures of the flesh and came home bursting with all the current ideas in art, music, fashion, and architecture; their thinking dominated by an all-consuming passion for the classical style of Rome.

Historian Iain Gordon Brown has identified the first mention of the Grand Tour as appearing in an early guide book circa 1670 which suggested: ''No man understands Livy or Caesar like him hath made exactly the Grand Tour of France and the Giro of Italy.''

The Tour, which saw thousands of young people and their tutors moving about Europe often lasted up to five years. In fact, some enjoyed the experience so much they didn't come home.

Best example is probably painter Gavin Hamilton from Lanark, who unearthed the biggest flowerpot in the world - the Warwick Vase - now the centrepiece of Glasgow's Burrell Collection. He went touring but settled in Rome. Gavin painted very serious classical stuff indeed. If I tell you that one of his jolliest efforts depicts Agrippina returning with the ashes of her dead husband, you'll get the drift. He took up archaeology, presumably to get a bit of fresh air.

Many of the professional antiquaries in Rome were Scottish, including James Byers who acted as city guide to Edward Gibbon who went on to write about the downfall of the Roman empire.

Gibbon recalls sitting in the Capitol in 1764 while bare-footed friars were singing vespers in the temple of Jupiter when the idea of writing his Roman history first came to mind. Jimmy Byers wouldn't have been far away.

But what about my sleazy detective? Well, in 1973 Morag and I were on our not-so-grand tour of Europe in our first home - a long wheel-base Land Rover.

In Paris we almost copped it in the Boulevard Hausmann when a 2CV slewed across the pavement; in Athens apart from being poisoned by exhaust fumes, Morag found

bottom-pinching was a way of life, and Rome, beautiful though it was, was a pickpocket's paradise.

But it was in Venice, home of baroque splendour and the Red Priest, that someone broke into the Land Rover and stole our few

luxury items including a wee radio and tape recorder. It was in reporting the theft, that we met the Italian sleuth. Straight out of a second-rate movie, he was.