28 September 1860, the Board of Admiralty decided to order three new iron-hulled ironclads: one large - Achilles, and two medium-size - Hector and Valiant. Though there was still great uncertainty as to the value of ironclads, and the Controller was directed to report as to their "fitness for use as transports or other duties in case it should be deemed advisable at any time to strip off their armour plates." On 7 February 1861 Rear Admiral Sir Baldwin Wake Walker resigned as Controller. He was replaced by Rear Admiral Sir Robert Spencer Robinson. Following a report from the British naval attaché in Paris regarding the progress of the French 1860 programme, the Naval members of the Board asked for the provision of ten new sea-going ironclads and the adaptation of ten or more existing steam line of battleships for armour protection with a total outlay of £3,000,000. The Prime Minister, Lord Palmerston, advocated cutting down and armouring the last sailing battleships rather than reducing the number of steam line of battleships. (In 1861, the fleet of steam line of battleships were extremely modern, and comprised the main battle strength of the Royal Navy.) The Chancellor of the Exchequer, William Ewart Gladstone, had decided in November 1859 that ironclads must be the vessels of the future. In early 1861, he was willing to accept a bigger appropriation for armoured ships if it could be offset by reduction in expenditure on wooden line of battleships. Gladstone suggested that the navy build wooden-hulled ironclads like the French. In March 1861, construction of the Bulwark-class two-decker steam line of battleships was suspended. Then in May 1861 it was decided to convert the five least complete ships of the Bulwark class into ironclads. It was also decided to lay down three new very large iron-hulled ironclads, which became the Minotaur, Agincourt, and Northumberland. Writing in December 1866, the Controller wrote: "The Caledonia and Ocean were ships of the line, of the largest class of two-deckers, in a certain state of advancement when in the Spring of 1861 I was appointed to the Controller’s office. The proposals I made in May 1861, to the Board, to convert these ships and three others into what they are now, was accepted, and I beg leave to call their Lordships’ attention to the concluding paragraphs of those submissions which in substance were as follows - "'No doubt is