SIR – There was an interesting view of the interior of Israel Newton & Sons boiler works, All Alone Road, Wrose, which TV personality Fred Dibnah visited in his series Made In Britain (T&A, August 21).

His widow, Sheila Dibnah, is promoting a new memoir on Fred, A Cast Iron Will.

Seemingly Newton’s engineering works, one of the last specialist boiler makers, is no more as the machinery has been removed.

The threatened buildings are the last visual reminder of an unusual method of extracting stone by mining rather than the traditional quarrying. They were the original stone sawing sheds.

As a young man in the 1930s I wandered Idle Moor to see open pit shafts, a clear sign of extensive mining.

Local historian William Cudworth in his book Round About Bradford tells us that Idle blue stone was of such quality that it was exported round the world.

There is a view that the underground workings are so extensive that Idle Moor is really hollow and filled with water.

A bit more of Bradford’s history gone?

R J Lacey, Wrose Road, Bradford