[2] In 1823 he and William Harris, a fellow architectural student, went to Sicily to look for evidence for the use of polychromy on ancient Greek monuments.
[3] While digging without permission in the ancient city of Selinus (Seliunte) they uncovered the broken pieces of some metopes from the frieze of the temple which showed traces of colour.
Their findings were published in 1826 as Sculptured Metopes Discovered Amongst the Ruins of the Temples of the Ancient City of Selinus in Sicily in the Year 1823.
At this time Angell was district surveyor for a 45-acre area of London encompassing the Liberty of Saffron Hill, Hatton Garden and Ely Rents, those parts of the parishes of St Clement Danes and St Mary-le-Strand within the liberty of the Duchy of Lancaster, and the precinct of the Savoy.
[7] He was one of two architects co-opted onto the committee charged with selecting the design for the new buildings for the Foreign Office (although only as an advisor without voting rights),[8] and in 1858 he was one of the witnesses questioned by the Select Committee of the House of Commons appointed to consider and report on the project, "in relation to the future Rebuilding of other offices on a uniform Plan".