Deepening mystery of disappearing microscope

About the "mud microscope"

Shortly before Christmas, a group of battered-looking items appeared on eBay for auction. Their source was surprising. During the 1980s, when the canals at Delft were being cleared, the mud that was dredged out was taken to help to reclaim land nearby at Het Delftse Hout (the Delft wood), an extensive country park. Amateur collectors have started sifting through some of this mud, and had turned up the items now offered for sale.