John Singer Sargent sawed his brush off, too. I presume it was for the reason I cited: sometimes you need to saw off a brush to fit in your pocket.
Traveling with My Schmincke Watercolor Paint and Feeling Happy
Essential Tips for Watercoloring Outside
American watercolorist, John Singer Sargent frequently painted en plein air from a gondola in the water rising and falling in the canals of Venice.
Art in the Center 