His design used a fast-beating balance wheel controlled by a temperature-compensated spiral spring. Spring tension is provided by a spiral spring in the base section. In 1850, Alexander Oechslin received an Austrian patent for an "improvement in spiral spring upholstery". The science of mechanics might perhaps suggest a means, namely, a strong spiral spring. The large spiral spring to hold the clutch in engagement is stationary. Traditional mechanical watch movements use a spiral spring called a mainspring as a power source.