Quote Originally Posted by RICHARD View Post
Well, now to find out if it started there.

I had heard a 'square meal' referred the dishes sailors used in the old days. When they has a mess call, a full ration covered the square dish they used - so that term came to represent a 'full' meal.

So I wonder if the plate came to be called a shingle?
The shingle is the toast. If you've ever had military mess toast, you'd understand why it came ot be called a shingle, the consistency is about the same.