hulls began in the 1830s; the first "warship" with an iron hull was the gunboat Nemesis, built by Jonathan Laird of Birkenhead for the East India Company in 1839. There followed, also from Laird, the first full-sized warship with a metal hull, the 1842 steam frigate Guadalupe for the Mexican Navy. The latter ship performed well during the Naval Battle of Campeche, with her captain reporting that he thought that there were fewer iron splinters from Guadalupes hull than from a wooden hull. Encouraged by the positive reports of the iron hulls of those ships in combat, the Admiralty ordered a series of experiments to evaluate what happened when thin iron hulls were struck by projectiles, both solid shot and hollow shells, beginning in 1845 and lasting through 1851. Critics like Lieutenant-general Sir Howard Douglas believed that the splinters from the hull were even more dangerous than those from wooden hulls and the tests partially confirmed this belief. What was ignored was that of wood backing the iron would stop most of the splinters from penetrating and that relatively thin plates of iron backed by the same thickness of wood would generally cause shells to split open and fail to detonate. One factor in the performance of wrought iron during these tests that was not understood by metallurgists of the day was that wrought iron begins to become brittle at temperatures below . Many of the tests were conducted at temperatures below this while the battles were fought in tropical climates. The early experimental results seemed to support the critics and party politics came into play as the Whig First Russell ministry replaced the Tory Second Peel Ministry in 1846. The new administration sided with the critics and ordered that the four iron-hulled propeller frigates ordered by the Tories be converted into troopships. No iron warships would be ordered until the beginning of the Crimean War in 1854. Following the demonstration of the power of explosive shells against wooden ships at the Battle of Sinop, and fearing that his own ships would be vulnerable to the Paixhans guns of Russian fortifications in the Crimean War, Emperor Napoleon III ordered the development of light-draft floating batteries, equipped with heavy guns and protected by heavy armor. Experiments made during the first half of 1854 proved highly satisfactory, and on 17 July 1854, the French communicated to the British Government that a solution