Fully controlled valve movement was conceived during the earliest days of engine development, but devising a system that worked reliably and was not overly complex took a long time. Desmodromic valve systems are first mentioned in patents in 1896 by Gustav Mees. Austin's marine engine of 1910 produced 300 bhp and was installed in a speedboat called "Irene I"; its all-aluminium, twin-overhead-valve engine had twin magnetos, twin carburetors and desmodromic valves. The 1914 Grand Prix Delage and Nagant (see Pomeroy "Grand Prix Car") used a desmodromic valve system (quite unlike the present day Ducati system).