(taken from source)
Millstone one was located during the cutting of base 9, in the south foundation trench, only about a quarter of this stone was seen. The remainder is still in-situ under the modern concrete pad. The stone is composed of a grey coarse grained granite. It is 43cm thick with chamfered edges and an estimated diameter of 1.8m. The stone sat on a pad of hard, coarse mortar about 5cm thick and some well-worn York stone slabs, probably representing the original factory floor were located around it. The millstone and floor were subsequently covered with brick hardcore and the concrete pad. Millstone 2 sat adjacent to millstone 1, it is composed of buff quartzite/limestone, 0.35m thick and with a maximum diameter of 1.8m. The top surface showed a pattern of extensive grooving and a shallow 'trough' some 62cm long, it also showed evidence of a dark, sticky residue which emitted a pungent, oily aroma. On the underside was a tapered iron fitting resembling a spindle or a spigot. As with the first milestone it sat on the York Stone and was covered with a concrete pad. Milestone 3 was represented by only two small fragments, which were left in situ. It was composed of coarse grey granite with heavily chamfered edges, 0.5m thick and with an estimated diameter of 1.6-1.8m. Only a narrow arc of millstone was visible of millstone 4 as it lay buried below the concrete floor and brick wall of a later cellar. The millstone was of buff quartzite/limestone, with a minimum thickness of 0.2m (the base was not seen) and with an estimated diameter of 1.7-1.8m. The upper surface showed evidence of a dark, sticky residue which emitted a pungent, oily aroma. The stone remains in situ.

All of the millstones were located within the limits of the old Oli Cake Manufactory that once stood at the site. The stones seem most likely to have been used for the crushing or grinding of oil bearing seeds for the manufacture of stock feed. Whether the stones are in their original position or have been dismantled and reused for another purpose is unclear. All of the stones do seem to have been placed deliberately set into the ground for a specific purpose; this is evidenced by the brick casting and pebble packing around the stones. The sticky residue on millstones 2 and 4 is probably the residue from crushed linseed. (1)

<1> Kent Archaeological Rescue Unit, 1999, Limekiln Street, Dover - report on an archaeological watching brief (Unpublished document). SKE6615.