Ancient markings on stones on the moors of Bradford have mystified generations of archaeologists.

What were our Neolithic or Bronze Age ancestors up to when they chiselled the grooves?

Were they communicating with the stars, or performing magical rites?

Last year a Bradford University technician, Gordon Holmes, speculated in his 2000: A Neolithic Solstice Odyssey, that these markings were used to signal changing seasons by crop farmers.

He said many of the more complex markings bore close similarity to star constellations such as Orion and Taurus.

Now, after more archaeological sleuthing, the ingenious Mr Holmes has come up with another timely deduction as his new book - 2000 BC: a Cup and Ring Trek suggests the markings may merely have been used to light fires.

To prove his point the former Boy Scout who lives at Selborne Terrace, Shipley, built a wigwam of sticks on Baildon Moor and photographed it.

He attributes his fire-lighter theory to what he calls a "fluke encounter" with a single carved rock at the LoadStone Beck Group, Baildon, which had metal inserted into the two hollowed-out cups.

If struck with a hard object the metal produces sparks.

He said: "There are at least 300 examples of cup and ring markings on the moors at Baildon, Bingley, Ilkley, Harden, and which vary considerably; but the standard pattern, I think, had a practical use. It may have been just like a fire-lighter to get the fire going elsewhere.

"They might have put some oil or animal fat on the rocks to disperse the heat and prevent the rocks from cracking," he added.

His latest book, due out in about three weeks, also proposes that Ilkley Moor's Swastika Stone symbol is in fact a Stone Age form of trigonometry in code.

Converted for the new archive on 30 June 2000. Some images and formatting may have been lost in the conversion.