I am looking for my family history, or to be precise - to find out if the family folklore is true. I want to identify the Nottingham pit (coal mine) where my great granddad discovered the River Trent to be full. He put in a pickaxe and started a slow leak, resulting in the first use of concrete (since roman times) to plug the little hole and save the pit. This story has been told to me by a couple of relatives, and there was a cartoon (I saw in the 70's during the miners strikes) of this ugly flat wall of concrete, with an inscription (by way of a finger) in it saying 'Calladine's Hole lies behind this plug'.

However, that has gone missing when my grandma died, and I can?t seem to find out any more details. When I were a nipper (kid), loads of folks in Sneinton, seemed to know the story (we moved there in 1977). Of course, the facts are blurred with time, I had thought that the Calladine in mention was in fact my Great Granddad Henry Calladine 1876-1951, as he had been a coal merchant in later life, but the facts don?t support this.

Historically the source of the real Calladines hole may his Grandfather, Daniel Calladine, but alas, he was a framework knitter who went to Nottingham in the 1790's where he met and married Elizabeth Brown, they returned to Heanor by 1897. So its not one of my direct line, but there are many cousins who were colliers in Heanor at the time. This fits in well with facts, as the concrete that was being used was 'roman concrete'.

Back in 1793, John Smeaton found that the calcination of limestone containing clay gave a lime, which hardened under water (hydraulic lime). He used hydraulic lime to rebuild Eddystone Lighthouse in Cornwall, England, which he had been commissioned to build in 1756, but had to first invent a material that would not be affected by water, but he did not patent it. Two years later (1796) James Parker of Hampshire patented a natural hydraulic cement by calcining nodules of impure limestone containing clay, called Parker's Cement or Roman Cement.

I think tat it is this Roman cement which was used to plug the hole, and not the later Portland cement. In 1824 Joseph Aspdin of England invented Portland cement by burning finely ground chalk with finely divided clay in a limekiln until carbon dioxide was driven off. The sintered product was then ground and he called it Portland cement named after the high quality building stones quarried at Portland, England. That material was (1828) credited to I. K. Brunel, who used it to fill a breach in the Thames Tunnel.

There were only a few pits open in Nottinghamshire at this time, but I have found proving this story so difficult to do. Perhaps it is just a myth, but if anybody knows for sure, I would love to find out.