In 1743, he served as a volunteer in the expedition led by Captain Charles Knowles (later a Rear Admiral) against the Spanish settlements and ships in the Caribbean and Central America.
Tonge then served with Colonel Hugh Warburton in the 45th Regiment of Foot first at Gibraltar and then at the Fortress of Louisbourg (1746 to 1749).
His regiment was assigned to garrison the new town of Halifax, Nova Scotia, where a fort was built.
After retiring from the army, Tonge received grants of land in Nova Scotia, where he settled.
He also served as justice of the Inferior Court of Common Pleas for Hants County and provincial superintendent of roads, bridges, and public works.