He later turned his attention to disparate and largely unsuccessful pursuits such as a fantastical design for caterpillar-like vehicles which he intended to replace railroad transportation, but did not manage to persuade anyone to give the design serious attention. In 1819, he travelled to England in an attempt to obtain financial backing from the Board of Longitude to build a device to determine longitude at sea. After initial difficulties, he was given an opportunity to address the Board, but his pretentious address, "On the Longitude", contained much philosophizing and generalities, but no concrete plans for a working device, and thus failed to gain any support from the Board. He remained for several years in England and, in 1821, published an introductory text on mathematics in London, which moderately improved his financial situation.