In Europe since the late 1840s, the king of Sardinia, Carlo Alberto, had been contemplating the excavation of a tunnel through Mount Fréjus to create a rail link between Italy and France, which would cross his realm. The need for a mechanical rock drill was obvious and that sparked research in Europe on pneumatic rock drills. A Frenchman, François Cavé (fr), designed a rock drill that used compressed air, which he patented in 1851. However, the air had to be admitted manually to the cylinder during each stroke, so it was not successful.