Smirke was a pioneer of using both concrete and cast iron.[19] A critic writing in 1828 in the Athenaeum said "Mr. Smirke, is pre-eminent in construction: in this respect he has not his superior in the United Kingdom". James Fergusson, writing in 1849, said "He was a first class builder architect ... no building of his ever showed a flaw or failing and ... he was often called upon to remedy the defects of his brother artist."[20]