The “Coin Test”: the generator does not vibrate and the coin stands up. Magic? No, Silengen!
Have you ever heard about the “test of the ten pences” exceeded in 1906 by the Rolls Royce cars? It is putting a coin standing up on the dashboard, turning on the car/engine and speeding up, the coin must stand in equilibrium. The “Times” newspaper considered the car dangerous because it was so silent that[…]