Ballistic Galvanometer , asking for 2nd time?

If u can specifically tell me abt tapping key's functioning related to ballistic galvanometer , is it related to electro magnetic damping , coz due to tapping short currents r induced in ckt which dampens the oscillation of the coil in the presence of electromagnetic field , also i nballistic galvanometer the coil osciallets in a vertical direction rather than horizontal one , why is that so . ?