Thing DO change...

... while you're back's turned.
We would notice, of course, that they changed, whenever it did occur; but this one I put in the shed with an idea to "save/collect" the different ones - and then - didn't.
It finally floated to the surface again in MUCH less than keepable condition , but - I thought I'd do a comparison since it felt a bit heavier.
It was.
I weighed 3 "new"/current ones. 241,244 & 268 gms I think they were. Whatever the figures, the 3 averaged 251gm.
The old one, extolling us to "Order our copy of "The 1987 Dairy Diary" which we didn't, weighed in at 350gms and both held/hold a pint of milk.

Just for fun:-
Is anybody old enough to remember when the "Top" was a card disk let into a recess around the top, and a weak point to poke a finger through to extract it?
VERY useful for making woolen Pom-poms.