  We have performed the first experiments in a superconductor - normal metal -
superconductor single electron transistor in which there is an extra
superconducting strip partially overlapping the normal metal island in good
metal-to-metal contact. Superconducting proximity effect gives rise to current
peaks at voltages below the quasiparticle threshold. We interpret these peaks
in terms of the Josephson-quasiparticle process and discuss their connection
with the proximity induced energy gap in the normal metal island.
