War notoriety), after which the 12-inch gun was universal. The Russians used both 12 and as their main armament; the , , , and had main batteries while the mounted guns. The first German pre-dreadnought class used an gun but decreased to a gun for the two following classes and returned to 11-inch guns with the . While the calibre of the main battery remained quite constant, the performance of the guns improved as longer barrels were introduced. The introduction of slow-burning nitrocellulose and cordite propellant allowed the employment of a longer barrel, and therefore higher muzzle velocity—giving greater range and penetrating power for the same calibre of shell. Between the Majestic class and Dreadnought, the length of the British 12-inch gun increased from 35 calibres to 45. and muzzle velocity increased from per second to per second. Secondary battery Pre-dreadnoughts also carried a secondary battery of smaller guns, typically , though calibres from 4 to 9.4 inches (100 to 240 mm) were used. Virtually all secondary guns were "quick firing", employing a number of innovations to increase the rate of fire. The propellant was provided in a brass cartridge, and both the breech mechanism and the mounting were suitable for rapid aiming and reloading. A principal role of the secondary battery was to damage the less armoured parts of an enemy battleship; while unable to penetrate the main armour belt, it might score hits on lightly armoured areas like the bridge, or start fires. Equally important, the secondary armament was to be used against smaller enemy vessels such as cruisers, destroyers, and even torpedo boats. A medium-calibre gun could expect to penetrate the light armour of smaller ships, while the rate of fire of the secondary battery was important in scoring a hit against a small, manoeuvrable target. Secondary guns were mounted in a variety of ways; sometimes carried in turrets, they were just as often positioned in fixed armoured casemates in the side of the hull, or in unarmoured positions on upper decks. Intermediate battery Some of the pre-dreadnoughts carried an "intermediate" battery, typically of calibre. The intermediate battery was a method of packing more heavy firepower into the same battleship, principally of use against battleships or at long ranges. The United States Navy pioneered the intermediate battery concept in the , , and classes, but not in the battleships laid down between 1897 and 1901. Shortly after