Peacock showed great ability in business and in the drafting of official papers. In 1829 he began to devote attention to steam navigation, and composed a memorandum for General Chesney's Euphrates expedition, which was praised both by Chesney and Lord Ellenborough. He opposed the employment of steamers on the Red Sea, probably in deference to the supposed interests of the company. In 1829 he published "The Misfortunes of Elphin" founded upon Welsh traditions, and in 1831 the novel "Crotchet Castle", the most mature and thoroughly characteristic of all his works. He was greatly affected by the death of his mother in 1833 and said himself that he never wrote anything with interest afterwards.