THAT amazing volume The Observer's Book of Automobiles, published by Frederick Warne and Co Ltd and constantly updated over the years, was an absolute bible of how the motor industry progressed and developed worldwide.

To my mind, the most interesting were the early volumes, and one of the first, published in 1955 is a real flashback into what was happening in the showrooms.

One of the most interesting entries concerns the Riley marque, which was fielding models which demonstrated both the grace of pre-war craftsmanship and the daring, more powerful modern look.

The volume lists the then current models as One and a Half litre saloon, one of the last gasps of the old RM Series and the then new Pathfinder saloon which was a very different animal.

The two showed a transition which was rapidly taking place and was an indicator of how the market was moving into a new age.

The old Riley company had passed into the hands of the Nuffield group in 1938 and had moved from its traditional Coventry home to Abingdon-on-Thames, Berkshire.

The RM series with its leather-cloth roof, Bentley-like front wings and running board had been a favourite among traditionalists who loved its British drawing room interior, long bonnet, split windscreen and superb comfort.

Under the bonnet was a 1496cc four-cylinder engine, which, when I one drove an example of this car always felt the it could do with a bit more power. Its 55bhp engine I found only adequate and the car could only stagger to 75mph.

But the more modern Riley in the showroom, the Pathfinder, had 100mph firmly I its sights.

In October 1953, there was a gesture to modernity in the old RM series with the switch to no running boards.

Produced from 1952, the One and a Half Litre was discontinued later in 1955 and ultimately its place in the range went in 1957 to the much shorter Riley 1.5.