I had originally fancied the pottery that washed up at Deptford was the result of the East India Company repairing its ships here. Porcelain was carried in the holds, serving as ballast, with the more precious and perishable tea on top, and so might be found littering the shore...but then I found blue and white further upstream, and also it wasn't porcelain, perhaps bone china, but mostly delftware or earthenware. The Museum of London then told me it was because everyone used to discard their rubbish in the river.
I later discovered this was the case up until the mid 19th century when the process of waste regulation began. The Public Health Act of 1875 charged local authorities with the duty to arrange the removal and disposal of waste. By the end of the 19th century household waste was collected daily in moveable ash bins, and was sorted by hand (usually by women or girls) into salvageable materials.
A large proportion of waste was recycled, but breeze (fine ash) and hard core (rough stuff) from incinerated material was used in building materials. The broken pottery I found in Kent was brought down with ash by Thames barges to the brick works, where bricks used to build the prospering cities and factories were handmade up until the early 20th century.
Martin from The Herb Garden came by at Creekside Centre and, seeing a rather weird shaped bit of pot in the mosaic, told me that porcelain sex toys used to be imported from China and the ships' cargo was often confiscated by customs and thrown in the river. That was why there was so much pottery washed up, he said.
Then I got an email from Cheryl who lives opposite the centre: "Thanks for your email about your show. Janet mentioned the willow patterned ballast dumping near here. Also that a marble dildo was jettisoned? I am doing my 3rd year dissertation on vibrators. Yes. Any material at all would be gratefully received."