I AM sure that, as Mr Isaacson writes, the pit was dug in the 1940s to get clay for repairing the river banks and some local people can remember when it was a grass meadow (Letters, June 14, 2007). But this is not the whole history of Roswell Pits. In

I AM sure that, as Mr Isaacson writes, "the pit was dug in the 1940s to get clay for repairing the river banks and some local people can remember when it was a grass meadow" (Letters, June 14, 2007).

But this is not the whole history of Roswell Pits. In the 1850s, the Rev O Fisher, a fellow of the Geological Society, referred to its venerable use as a quarry to "make up the banks in the fens". An earlier mention in the Fen Office documents of a sluice gate at "Rossall" in 1659, and of a reference to removal of earth in 1698, for instance, suggests that the pits were already being used as a quarry, and that there had been a need for a sluice, for some years before. Indeed, medieval references to Ely Lode seem to imply that Roswell might have been used as a quarry far earlier still.

It is a central principle of conservation we should understand the historic uses, and names, of sites when considering their future. We must all try to avoid filtering our history to make it support our present preferences. The Roswell Pits have been around a little longer than the 1940s.

NEIL HITCHIN

Bishop Wynn Close

Ely