Nemesis was the first British ocean-going iron warship. She was the largest of a class of six similar vessels ordered by the 'Secret Committee' of the East India Company. Nemesis, together with her sister ships Phlegethon, Pluto, Proserpine, Ariadne, and Medusa, was built by John Laird’s yard at Birkenhead and William Fairbairn & Sons at Millwall. Launched in 1839, the Nemesis was deployed to China – arriving late 1840 – and used to great effect in the First Opium War by Captain William Hutcheon Hall and later in 1842 by Captain Richard Collinson. The Chinese referred to her as the "devil ship". Construction Although commissioned by the Secret Committee of the East India Company (EIC) in 1839, the vessel did not appear in the EIC's list of ships, leading The Times to comment: "...this vessel is provided with an Admiralty letter of license or letter of marque. If so, it can only be against the Chinese; and for the purpose of smuggling opium she is admirably adapted." Nemesis was a gunboat built by British shipbuilding company John Laird's Birkenhead Iron Works in three months. She had a length of , a beam of , a draught of when full of coal and less than 5 ft when laden with less, and a burthen of 660 tons. She was powered by two sixty horsepower Forrester engines. She was armed with two pivot-mounted 32-pounder and four 6-pounder guns. The steam- and sail-powered ship was particularly effective in China because her shallow draught of only five feet allowed her to travel up rivers to pursue and engage other vessels and targets. Her watertight bulkheads were the first to be used in a warship. They enabled her to survive the hull damage she sustained during sea trials and en route to China in 1840. In July 1840, Nemesis became the first iron ship to sail around the Cape of Good Hope, aided by techniques developed the year before by Sir George Airy, the Astronomer Royal, to adjust a compass for the effect of an iron hull. The adjustments were not particularly effective, with the result that the ship's compass performed poorly throughout its career. China Nemesis arrived off the coast of China in late 1840, although when she set sail from Liverpool it was publicly intimated that she was bound for Odessa to keep the voyage a secret. A British officer wrote that the