A power transmission for a turbine or a compressor has a housing, a first shaft rotatably mounted so as to be rotatable in one direction in the housing, a barrel rotatably mounted so as to be rotatable in a direction opposite to that of the first shaft within the housing, a first plurality of blades affixed to the first shaft and extending radially outwardly therefrom, and a second plurality of blades affixed to the barrel and extending inwardly therefrom. Each blade of the second plurality of blades is interposed between adjacent blades of the first plurality of blades. A second shaft is mounted exterior of the housing so as to drive the barrel in rotation.