THOUGH Christmas was in the offing when the icing went on this monster cake in Blackburn 39 years ago, the festive occasion it was baked for was the marking of a major milestone in the town's industrial history -- and the 80th birthday of the man who helped it happen.

He was electronics industry pioneer, Londoner Stanley Mullard -- seen left admiring the work of confectioners Mrs R. Dewhurst and Mr R.Crompton -- and in 1920 had formed the radio valve company that bore his name.

But it was the Surrey-based company's setting up a factory in Blackburn in 1938 -- at a time when its cotton industry was in deep slump and 16,000 were out of work -- that was to have a massive impact on jobs and the town's economy.

Part of the giant Dutch-based Philips electronics empire, the new Little Harwood factory -- initially known as the Philips Works -- was originally intended to make light electrical equipment. But it was the outbreak of war the following year and the Nazi blitz of 1940 that was to create a huge jobs explosion there.

For the production of valves -- so vital for military radio communications and radar -- was switched from Mullard's giant Mitcham works to Blackburn to escape the bombing raids on the South East.

The original workforce of 200 at Blackburn quickly ran into thousands as the first year's output of 60,000 valves in 1940 soared past the million-mark within 12 months.

And output, the factory itself and jobs just kept on growing -- with production and employment really rocketing in the 1950s when the ending of post-war austerity saw millions of families getting their first TV sets, all of them filled with valves.

By 1954, the factory site had spread to 45 acres and 3,300 people -- many of them women -- worked in what had grown to be the biggest valve plant in Europe. It became the first Philips' factory to run round the clock, but even when the payroll shot up to more than 4,500 as the output of valves was peaking at nearly 57 million by 1959, demand meant production had to be farmed out to another seven 'feeder' factories in Lancashire employing another 1,500 workers.

In late 1963 -- just as Stanley Mullard reached 80 -- the Blackburn plant made its 500,000,000th valve. And a civic tribute was paid to both occasions at a special banquet at the town's Windsor Hall, at which a special feature was the monster cake, decorated with dozens of valves and topped by a model of the giant works.

Town council leader Alderman George Eddie told how the Mullard was putting £3.5million a year in wages into the local economy -- the equivalent today of £45.4million -- and said that if the plant suddenly went out of existence Blackburn's rates would soar by two shillings to three shillings (15p) in the pound -- a 200 per cent increase.

Mr Mullard was presented with the 500,000,000 valve, which had been specially mounted. But as the milestone and the valve's contribution to the prosperity of thousands of East Lancashire was marked that year, a turning point was being reached, with transistors -- invented in 1947 -- and later microchips -- starting to take their place alongside valves in the new generation of TV sets and radios.

Even so, the works was still turning out nearly 55 million valves a year and production of them was to carry on at Blackburn until January, 1982, by when it had become the western world's very last valve factory. In all, it made a more than a billion of them -- 1,004,633,314 to be exact.

Now, the giant works is host to dozens of other companies as an industrial park and Mullard's successor at the plant, LG Philips Displays, which supplies monitor tubes for TV and computers, employs less than a tenth of the payroll of the factory's hey-day and is cutting the workforce by a third.