This paper describes some calculations using the digital computer programme written by Marsh 1 for the through-flow fluid mechanics of a turbomachine. The machine chosen as the subject for the calculation was a slow-speed single stage axial flow compressor in the Mechanical Engineering Department at Liverpool University. The deviations and losses for the blades were obtained from cascade correlations and the area blockages and secondary flow angle changes were derived from a simple annulus wall boundary layer calculation performed on an analogue computer.