I'm normally a pretty observant person, Harvey, but this whole patten thing has thrown me. It completely passed me by. We live and learn.(-:
As for the chamber-pot emptying from windows, that was quite common for several centuries including the nineteenth. The origin of the word "loo" is interesting: "The British call their toilets "the loo". This slang term comes from the French phrase "Guardez le' Eau. Which translates to "watch out for the water". This was often the only warning you got before the contents of a chamber pot came hurtling through someone's window.". Not the choicest subject in the world, but all part of normal life that we tend to class as the "unmentionables" and...well, just don't mention them.(-:
I was born into a row of terraced houses in industrial Lancashire. We had no bathrooms and just a large tin bath that had to be filled, Austen style, with kettles of boiled water. We also had chamber pots that got emptied into a "Tippler" toilet at the end of the backyard. Fortunately, things have moved on a little now..Always good to remember your roots though....(-: