Heinlein's "Have Spacesuit, Will Travel" (1958), p14 in my copy:
"I remember once, when the money baskey was empty, Dad told Mother that "a royalty was due." I hung around that day because I had never seen a king (I was eight) and when a visitor showed up I was disappointed because he didn't wear a crown. There was money in the basket the next day so I decided that he had been incognito (I was reading The Little Lame Prince) and had tossed Dad a purse of gold-it was at least a year before I found out that a "royalty" could be money from a patent or a book or business stock, and some of the glamour went out of life."
"I remember once, when the money baskey was empty, Dad told Mother that "a royalty was due." I hung around that day because I had never seen a king (I was eight) and when a visitor showed up I was disappointed because he didn't wear a crown. There was money in the basket the next day so I decided that he had been incognito (I was reading The Little Lame Prince) and had tossed Dad a purse of gold-it was at least a year before I found out that a "royalty" could be money from a patent or a book or business stock, and some of the glamour went out of life."