h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Your article on egg preservation brought memories of my early childhood in the late 1950s, flooding back. We had hens when I was little and my parents used to preserve their eggs in water-glass. I seem to recall the name Ising Glass or something similar but I don't know if I'm imagining it or not.
I also recall a china egg we used to put in with the hens to encourage them to lay and roughly crushed seashells we mixed with their food to help the eggshell production.
I must admit that this also brings back memories of a simple but effective contraption we used to have in a outhouse for breaking chickens' necks, almost like a metal nutcracker attatched to the wall. Strangely, although I couldn't bear to witness it now, I had no problem as a child watching its use nor the gutting of the birds once dead.
I had forgotten all these things until now.