Pestarini also visited the United States in 1930, although there is no record of the system being used there. The General Electric engineers, led by Ernst Alexanderson, were interested, but modified the design by the addition of a compensating winding, which counteracted the effect of the flux produced by the load current. This turned the machine from a voltage-to-current amplifier into a voltage-to-voltage amplifier, and they called the new variant an Amplidyne. The development costs were largely funded by US naval contracts for the development of vertical stabilisers, which were used to improve the aiming and firing of guns on ships. During the same period, the Macfarlane Engineering Company, who were based in Glasgow, developed a variant of the cross field machine quite independently, which they named the "Magnicon".