Look, we're all terrified of premature burial. That's why my casket will have mechanized legs, a self-contained life support system and a wireless Internet connection.
But our predecessors were not so lucky. Before modern embalming techniques came along to make live burial impossible (and supplant it with fears of merely being embalmed alive), it seemed an incredibly possible fate. You might just wake up in the dark of a casket six-feet deep.
And sure, it happened, but never more than 2 percent of the time. Still, some folks worried over such a ghastly fate and devised means by which the dead might be inspected in the casket through a glass window, as well as means by which the dead might communicate with the surface world. They'd ring a bell, shout up through a breathing tube or, as we see in this image, bust open the lid entirely. Here's what the National Archives says about this 1843 design:
So there you have it. It's a perfect way to save your life if you're buried alive, or to ruin a funeral if you're just a corpse shifting due to rigor mortis.