Aside from its exterior being made of sandstone, Fort Niagara's Hot Shot Furnace looks exactly like just about every other such American furnace of the period, with those distinctive star braces and its coal box and ash pit located along the side.

Note the wall to the furnace's right, and the difference in building materials: The riverside wall was started in 1816, but money and interest in this endeavor ran out before it could be completed: The wall was finished during the 1839-1844 improvement period...with enough sandstone left over to build a Hot Shot Furnace!