  Recently, in an ensemble of small spheres, we proposed a method that converts
the force between two large spheres into the pressure on the large sphere's
surface element. Using it, the density distribution of the small spheres around
the large sphere can be obtained experimentally. In a similar manner, in this
letter, we propose a transform theory for surface force apparatus, which
transforms the force acting on the cylinder into the density distribution of
the small spheres on the cylindrical surface. The transform theory we derived
is briefly explained in this letter.
