Thanks all, keep them coming!
I've just had to look up "washing dolly", the ceiling-mounted rack with ropes and pulleys, I didn't know it was called that. My grandmother had one, which squeaked loudly when it was raised or lowered.
Also the "Salter" bread slicer, with handle to turn sharp blade.
Whistling stove-top kettle.
Extra sideboard which slid out of the kitchen unit - great for a small kitchen, I've never seen one anywhere else.
A single very old-fashioned gas hob, which could easily be disconnected from the gas outlet. The gas safety inspectors always condemned it every time, but she persisted in using it.
Electric servant bells in most rooms, complete with indicator in the "breakfast room" to show which one was rung. (No servants though - that was inherited with the house.)
Electric oven which could be timed to switch on automatically. They seem to be old-fashioned now - are they considered too dangerous, like leaving cooking unattended?
With the famous twin tub, it was not automatic, you had to do the cycles yourself: put water and powder in, switch heater on, "agitate" the clothes (propeller would spin round), drain water into the sink, pump in clean water, "agitate" again, pump water out. Spin drier was allegedly powerful enough to rip your arm off, if you opened the lid and put your arm in while it was still spinning.
A gadget for embossing a letter with the address, and phone number, which was of course alphanumeric, i.e. "Brixton 7215" or similar.
Vintage metal toys, very different from today's plastic stuff.
Here's a game to play while watching the film Miss Peregrine's Home for Peculiar Children: lots of the things mentioned on this thread can be seen in the background.