An electro-mechanical analogue computer has been described which simulates in conjunction with the 10-kc power amplifiers in the Network Analyzer the rotor inertia and the governor of a synchronous generator. The computer eliminates the need of tedious, time-consuming, step-by-step calculations in a transient stability problem and makes possible a more accurate analysis;The computer requires further development in order to maximize its capabilities and broaden the scope of inquiry possible with it. The application of the computer to non-linear problems outside the power system field is desirable and should be investigated.