Jack London also used it in To Build A Fire (1908), his grim short story about a man trying to survive in sub-zero weather:
Fifty degrees below zero meant eighty-odd degrees of frost. [...] Fifty degrees below zero stood for a bite of frost that hurt and that must be guarded against by the use of mittens, ear-flaps, warm moccasins, and thick socks.I think the term doesn't get much use these days. It's time to resurrect it!
When Mrs Elliott and I awoke this morning it was 17 degrees Fahrenheit outside, or