he enlarged, possibly using some of the stonework from Columb John. Columb John thus became merged into the estate of Killerton. References Further reading Gray, Todd & Rowe, Margery (Eds.), Travels in Georgian Devon: The Illustrated Journals of The Reverend John Swete, 1789-1800, 4 vols., Tiverton, 1999, vol.4, pp. 210–11 Historic estates in Devon