From 1875 onwards, the balance between breech- and muzzle-loading changed. Captain de Bange invented a method of reliably sealing a breech, adopted by the French in 1873. Just as compellingly, the growing size of naval guns made muzzle-loading much more complicated. With guns of such size there was no prospect of hauling in the gun for re-loading, or even re-loading by hand, and complicated hydraulic systems were required for re-loading the gun outside the turret without exposing the crew to enemy fire. In 1882, the 81-ton, 16-inch (406 mm) guns of fired only once every 11 minutes while bombarding Alexandria during the Urabi Revolt. The 100-ton, 450 mm (17.72 inch) guns of could each fire a round every 15 minutes.