Today, we usually eat off round plates like this. But they’re a bit rubbish if the sea’s rough.

Funnily enough, Gareth is quite good at doing an impression of a rough sea. Whoops! Crash!

Where are the limes, Gareth?

No, that’s a square wooden plate. Which might have been better for not sliding around in rough seas as much, but it’s not a lime.

Anyway, it’s believed that this is where the expression ‘a square meal’ originated.

You’d think, after all this time, we’d have sorted out that problem the How2 studio has when it’s stormy outside.

But apparently not. It has a bit of a tendency to sway around. Still, at least that makes it easy to simulate ship’s meal time on the high seas.

Well, fairly easy, anyway. Get the plate down, Gareth!

Midshipman McKenna doesn’t seem to happy by the meal she’s been offered, though. Let’s see what it is.

Dried meat, boiled in salt water. Yum.

Here’s an alternative: dried fish, boiled in salt water. Tasty.

But not, evidently, to Midshipman McKenna’s liking.

And if she fancies some fresh fruit or vegetables, she’s out of luck – in the middle of a long sea voyage there’s no chance they’d keep. The trouble is, without fruit and veg, neither do humans.

With poor diets, sailors of the time develop sores on their skin…

…their gums start to bleed…

…and eventually their teeth start to fall out.

They also suffered massive emotional swings, and…

…terrible tiredness. And of course, the disease the sailors had was scurvy. A few hundred years ago the situation became so bad, the Royal Navy lost more men to scurvy than they did in battle.

The cause of scurvy is a diet lacking in vitamin C – which is found in fresh fruit and vegetables. But the solution for sailors came in the form of… limes!

See, I knew there’d be limes in this How. Lemons, too. Citrus fruits like these are particularly rich in vitamin C, and they keep well because they’re so acidic.

By the end of the eighteenth century, sailors’ rations included lots of lemons and limes, to make sure they got enough vitamin C.

Within months, the lemons and limes were saving lives – so that’s how healthy a square meal became.