In 1794, he travelled to Italy (with another young architect, Charles Tatham) at the expense of John Martindale, proprietor of White's, and remained there until the advance of Napoleon's army in 1797.

[1] Commercially he was a failure and served two terms in a debtors' prison, but his published and exhibited work was largely a critical and popular success.

He intended to expand upon this subject in an eight-volume work entitled Art, Philosophy and Science of Architecture, of which his unpublished manuscript survives.

His paintings show a dramatic use of two-point perspective and architectural precision, and also reflect his (and Soane's) fascination with Roman ruins.

His architectural fantasies owe a clear debt to Piranesi and play upon historical, literary and mythological themes, with a feeling for the sublime that is the equal of his contemporaries J. M. W. Turner and John Martin.