time. The designs for the two ironclads were got out at the Admiralty by Mr Watts, Chief Constructor of the Navy, in consultation with Mr Scott Russell, and identical drawings were sent to the contractors, the Thames Iron Shipbuilding Company and Messrs R. Napier & Sons, of Glasgow, for their information and guidance. The engines were in every way duplicates, of course. And yet the 'Warrior' was, and is to this day, appreciably superior, both in steaming and sailing, to the 'Black Prince.' Many ingenious explanations for this difference were proposed, but none that could in any way be called convincing.
At the latter end of 1860 the Admiralty, being perturbed in their minds at the large amount of the national coal bill, gave carte blanche to three eminent engineering firms to construct machinery for three crack sailing frigates of nearly similar tonnage and lines, with the sole view of combining reasonable speed with economy of fuel. The selected frigates were the 'Octavia,' Arethusa,' and 'Constance,' which were assigned to Messrs Maudslay, Penn, and Randolph & Elder respectively, with no restrictions as to pattern or, it was said, price. Messrs Maudslay elected to supply a three-cylinder engine, working expansively in the ordinary way, with an initial pressure of 30 lbs., which they afterwards reproduced on a larger scale in the 'Lord Warden'; Messrs Penn fitted an exceptionally well executed specimen of their trunk engine, but about neither of these designs was there any decided novelty. The Scotch firm, however, flew at higher game. They had
