Gunpowder Factory at Waltham Abbey. It entered British service in 1891 as Cordite Mark 1. Its main composition was 58% nitro-glycerine, 37% guncotton and 3% mineral jelly. A modified version, Cordite MD, entered service in 1901, this increased guncotton to 65% and reduced nitro-glycerine to 30%, this change reduced the combustion temperature and hence erosion and barrel wear. Cordite could be made to burn more slowly which reduced maximum pressure in the chamber (hence lighter breeches, etc.), but longer high pressure – significant improvements over gunpowder. Cordite could be made in any desired shape or size. The creation of cordite led to a lengthy court battle between Nobel, Maxim, and another inventor over alleged British patent infringement. Other shell types A variety of fillings have been used in shells throughout history. An incendiary shell was invented by Valturio in 1460. The carcass shell was first used by the French under Louis XIV in 1672. Initially in the shape of an oblong in an iron frame (with poor ballistic properties) it evolved into a spherical shell. Their use continued well into the 19th century. A modern version of the incendiary shell was developed in 1857 by the British and was known as Martin's shell after its inventor. The shell was filled with molten iron and was intended to break up on impact with an enemy ship, splashing molten iron on the target. It was used by the Royal Navy between 1860 and 1869, replacing heated shot as an anti-ship, incendiary projectile. Two patterns of incendiary shell were used by the British in World War I, one designed for use against Zeppelins. Similar to incendiary shells were star shells, designed for illumination rather than arson. Sometimes called lightballs they were in use from the 17th century onwards. The British adopted parachute lightballs in 1866 for 10-, 8- and 5-inch calibers. The 10-inch wasn't officially declared obsolete until 1920. Smoke balls also date back to the 17th century, British ones contained a mix of saltpetre, coal, pitch, tar, resin, sawdust, crude antimony and sulphur. They produced a "noisome smoke in abundance that is impossible to bear". In 19th-century British service, they were made of concentric paper with a thickness about 1/15th of the total diameter and filled with powder, saltpeter, pitch, coal and tallow. They were used to 'suffocate or expel the enemy in casemates, mines or between decks; for concealing operations; and