The construction and use of barium titanate ceramic transducers for fine-movement control is described. The movement obtainable for unit applied voltage is approximately 0.25 μm kv^-1, a maximum working voltage per unit thickness of the ceramic of 3.5 kv mm^-1 being possible. The maximum movement obtainable for a given overall voltage can be increased by lamination of the ceramics. Parallel movement of a plate is provided by the use of three transducers as supports; the expansions of such supports are identical to within 5 nm for a movement of 2.5 μm.