From the archives of Bob Montgomery, motoring historian

AT THE SIGN OF THE BALD FACED STAG ... Spark plugs are something the modern motorist takes for granted. Indeed, few of today's motorists ever see a spark plug, let alone realise its key role in the efficient and reliable running of their car's engine. It was not always so, and the fact that it is now is in no small way due to the persistence of a young Irish racing driver who became frustrated with the unreliability of the sparking plugs fitted to his French-built Darracq in 1912.

That young man was Kenelm Lee Guinness, of the brewing family, and he was, in his own words, "mad about racing". While studying at Cambridge University he had acted as mechanic to his older brother, Sir Algernon Guinness. Upon leaving Cambridge, Kenelm had taken up racing on his own account and found a home for his racing sable in some outbuildings at an old disused inn called The Bald Faced Stag at Putney Lane on the London to Portsmouth road.

Up until around 1912 spark plugs more or less performed satisfactorily, but the introduction of smaller, higher revving engines showed up the deficiencies in their performance. It was while at the Isle of Man Tourist Trophy Race that Kenelm became so frustrated with his plugs that he resolved to make a better performing spark plug. Kenelm began to experiment at The Bald Faced Stag and decided to try other materials rather than the porcelain which was then used for the insulation of spark plugs. In mica he found what he was looking for, and produced a small batch of mica-insulated plugs of his own design. The results were highly satisfactory and soon his racing friends were asking him to produce more for their own use.

Thus production began in a small way at the old inn and before long demand was such that Kenelm entered into large-scale production.

Special plugs were also designed to meet specialist requirements, and in particular for the needs of the aircraft of the Royal Flying Corps, later to become the Royal Air Force. With the outbreak of the first World War, Kenelm had joined the Royal Navy, but such was the success of his spark plugs, (marketed under his initials KLG) that he was asked to resign in order to concentrate on the production of plugs for the armed services.

By the end of the war, KLG plugs were famous among aviators throughout the world and the production lines at The Bald Faced Stag took the form of a modern factory employing some 1,500 workers.

From 1919 until the outbreak of the second World War, KLG spark plugs were used in almost every motoring, motorcycling or flying achievement of note, and in addition several special engines and two complete record breaking cars were produced in one of the garages at the Putney factory. The cars were Sir Henry Segrave's beautiful "Golden Arrow" and Sir Malcolm Campbell's "Bluebird", both of which were to hold the World Land Speed Record.

Kenelm continued to race until 1924, when his Sunbeam crashed in the San Sebastian Grand Prix, killing his riding mechanic and seriously injuring him. When the Irish Grand Prix was staged in Dublin's Phoenix Park, Kenelm gave valuable advice to the organising club and acted as an official for the event. Kenelm Lee Guinness, who made the first "modern" spark plug, died in 1937.