In order to observe the effect of transverse fluid forces on a particle in turbulent shear flow unobscured by a parallel gravity effect, a weak suspension of particles was circulated round a pipe loop with two long, vertical legs. Systematic shifts of concentration were observed in the vertical legs which could be attributed neither to symmetrical diffusion nor entirely to excess normal stress away from the boundary. An explanation of the results is offered based on the simultaneous action of excess normal stress and a lateral force due to circulation round each particle.