The paper presents an elementary approach to the theoretical considerations upon which electrical analogues can be used to simulate hunting phenomena in power systems. The major assumption is that in the case of a deviation of the pole axis of the rotor of a machine from its normal steady-state condition, the amplitude of such angular displacement must be small. As an example, a simple electrical analogue is set up to simulate a given electro-mechanical system. The frequency and amplitude of natural oscillations determined experimentally on the analogue agree very well with the results of a mathematical analysis.In order to extend the scope to system stability problems, a 10-kc/s network analyser utilizing analogue-computer technique is described. The main object is to produce a unit capable not only of solving steady-state stability problems, but also of producing directly the system swing curves for transient problems, without the necessity for step-by-step computations, as are required with the usual a.c. network analyser. Further work on this analyser is being carried out and will be reported in a future paper.