11th July 1859: The Elizabeth Tower was completed in May? 1858 the following year on 11th July 1859 the second bell Big Ben, since the first was cracked during testing, tolled for the first time! Unfortunately this bell too cracked in September 1859, according to the foundry's manager, George Mears, Denison had used a hammer more than twice the maximum weight specified. Big Ben was out of commission for three years.
