could have been washed down. Although Frere's letter was officially read at the Society on 22 June 1797, and published by it in 1800, his interpretation was so radical by the standards of the day as to be overlooked for six decades, until noticed by John Evans.

Frere's is considered one of the most important middle Pleistocene sites in Europe, because of what he observed in his letter: juxtaposition of artefacts, animal remains and stratigraphic evidence. Its significance is double: