In the summer of 1925, an informal ceremony was held in the Memorial Chamber, where in Governor General of Canada the Viscount Byng of Vimy; Prime Minister William Lyon Mackenzie King; Leader of His Majesty's Loyal Opposition Arthur Meighen; and the Commander-in-Chief of the British forces during World War I, the Earl Haig, laid the base stones of the clustered marble columns that support the fan vault ceiling. The Prince of Wales then returned to Ottawa again in 1927 to dedicate the altar of the Memorial Chamber and to inaugurate the Dominion Carillon, the first playing of which on that day was heard by listeners across the country on the first ever coast-to-coast radio broadcast in Canada. Upon completion, the Peace Tower stood as the tallest building in Ottawa as well as the whole of Canada.