CANADAIR C-4 'North Star'. aka the 'Argonaut' in BOAC service.
This is a lengthy essay on this significant post-WWII pressurised airline type which will be recalled by many UK and Canadian readers. The use of the Rolls-Royce Merlin engine is interesting given that the use of liquid-cooled powerplants in post-war civil air transport types was rare, unusual and controversial.