Living in the midst of a most interesting geological district, his quick appreciation could not fail to be struck with its interesting characteristics. As on his professional visits, he rode or drove over the South Downs and Weald of Sussex, he was continually searching for the organic treasures imbedded in the quarries or lying by the roadside, which afforded him an inexhaustible source of delight and instruction; and he thus accumulated materials which eventually enabled him to establish the fresh-water character of the Wealden,—a discovery which alone will hand down his name to the latest posterity as one of the great founders of the science of Geology,—and brought together the fragments of fossil bones which afterwards gave him the power of building up the skeletons of those gigantic reptiles, the hyleosaurus, iguanodon, pelorosaurus, and others, with which he astonished and delighted, not only the public generally, but the scientific world. The number of specimens so collected amounted to upwards of 1,200, and with these he founded the Mantellian Museum, which was visited, while he lived at Lewes, by the most eminent men of the day; among others by Baron Cuvier, and by the Royal Princes. This collection he afterwards removed to Brighton, when he went to reside there, and he made great efforts to have it established in the county from the strata of which it had been gathered, as the nucleus of a local geological museum, but the requisite funds were not forthcoming, and it was ultimately sold to the British Museum...
Gideon Mantell