Whipple manufactured Boston Gunpowder at the improved mill until 1855 ; .
Whipple began moving gunpowder manufacturing operations to a more remote location on Maine 's Cumberland and Oxford Canal in 1833 to minimize risks of accidental explosions and to be closer to supplies of charcoal .
Whipple manufactured Boston Gunpowder at the improved mill until 1855 ; although he began moving gunpowder manufacturing operations to a more remote location on Maine 's Cumberland and Oxford Canal in 1833 to minimize risks of accidental explosions and to be closer to supplies of charcoal .