‘Rolled up Tin’

No, it's not a turbofan jet engine. It's much more mundane than that!

Following Sunday's blip about the holes left after the railings were removed during World War II, here is another example of an object that may be regarded as a military relic.

I've always been fascinated by the rectangular tins in which corned beef (and Spam) still come and, as a child, got a peculiar satisfaction from using the key supplied to open them. If you managed to do so successfully, you ended up with a nice little strip of metal neatly rolled around the key.

The tins are rectangular because corned beef has been a staple military ration for hundreds of years, and the shape means that you can pack the cans as densely as possible and stack them more securely on shelves. Historically, the fact that you didn't need a separate tool to open the cans was also a significant advantage in a military context, and the tradition has stayed.