From the following entries at Google we can locate Edgar Ewan Horne in Kenya from at least May 1948 to June 1953.
Kenya Gazette - 25 May 1948 Vol. 50, No. 21 - Magazine Edgar Ewan Horne, Inspector of Police, to be Chief Inspector of Police with effect from 1st January, 1948. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Kenya Gazette - 4 Oct 1949 Vol. 51, No. 45 - Magazine Edgar Ewan Horne Chief Inspector of Police, ... ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ SUPPLEMENT TO THE LONDON .GAZETTE, 1; JUNE, 1953
...on the occasion of Her Majesty's Coronation, The Queen approves the award of Colonial Police Medal for Meritorious Service to Edgar Ewan HORNE, Superintendent, Kenya Police Force.
Any further information as to when he and his son moved to Shawnigan ?.....or the name of his son?