phrase roots

I've got two interesting phrase roots for you.

Both involve British sailors and ships of the line.

First, they were all allocated one glass of rum and water (called "grog") and their own square plate, to fit the crowded tables between the cannons. That's why they called it a "square meal".

Second, and more interestingly, often times when the ships came to port, they didn't let the sailors off, because it was so common to abandon your ship and not return. So while they were in port, the wives and women would often come up and live on the decks for extended periods of time, until they shipped out again.

If a woman went into labor, and it was a difficult labor, sometimes they would take her down below, and fire a cannon right next to her, which they believed would aid in the childbirth, kind of pushing the baby along. If they did this and the child was born, they would call it a "son of a gun."