US blizzard: Charting the snow depth - using six dogs
The north-east of the US has endured a succession of snowstorms. The BBC's Franz Strasser looks at the historical numbers - and uses an unconventional measure to chart how deep the snow is in Boston.
Snow depth in Boston 10 Feb 14:00 GMT (09:00 EST)
Snow depth in Boston 27 Jan 22:00 GMT (17:00 EST)