Major Francis C. Marshall of the Second United States Cavalry will discuss the question "Is our Nation Prepared?" in the Assembly Room of the Union Monday evening at 8.15 o'clock. The address will be given under the auspices of Troops B and C, both composed largely of Harvard-men. The meeting, which will be open to the public, is partly in celebration of the anniversary of Troop C, which was organized in the Union three years ago.