Following the 1875–76 Royal Commission into the Volunteer Forces, the Victorian Government invited the Director of Works and Fortifications in London, Lieutenant General Sir William Jervois, to Victoria to further advise on Victoria's defences. He arrived in 1873 accompanied by the Colonel Scratchley. Their joint report recommended that the basic defences for the Colony should be concentrated on the Heads, and consist of fortifications at the entrance to the Bay and on the shoals between the main shipping channels.