planchette(n = noun.artifact) Array - a triangular board supported on casters; when lightly touched with the fingertips it is supposed to spell out supernatural (or unconscious) messages; Array
is a kind of board
is a part of ouija, ouija board

1.  A circumferentor. See Circumferentor. [1913 Webster]

2.  A small tablet of wood supported on casters and having a pencil attached. The characters produced by the pencil on paper, while the hand rests on the instrument and it is allowed to move, are sometimes translated as of oracular or supernatural import. [1913 Webster]

planchette, n. a small usu. heart-shaped board on castors with a pencil that is supposedly caused to write spirit messages when a person's fingers rest lightly on it.

Etymology:
F, dimin. of planche PLANK