Among other famous iron vessels which were either specially built or employed as Royal yachts in the middle of the last century may be mentioned the _Jerome Napoleon_, constructed by M. A. Normand at Havre for the late Prince Napoleon, afterwards Emperor of the French; the _Peterhoff_, built by Messrs. Ditchburn and Mare at Blackwall in 1850 for the late Emperor Nicholas of Russia, which was wrecked on her outward voyage to the Baltic; the _Falken_, built at Deptford in 1858 by Messrs. C. Langley for the late King Frederick VII. of Denmark. She was an iron schooner-rigged vessel 127 feet in length, and could steam at 10 knots an hour. The _Miramar_ was a favourite yacht with the late Empress of Austria. The Russian Imperial Yacht _Livadia_ was circular and shallow, and is the only large turbot-shaped yacht afloat. These yachts, however, have been gradually superseded by vessels of a thoroughly modern type. As a case in point, the _Princess Alice_, owned by H.S.H. the Prince of Monaco, and constructed by Messrs. R. and H. Green at Blackwall in 1891, is built of steel frames with teak planking, her bottom being covered with copper sheeting. Thus in her general finish she is one of the finest specimens of marine architecture on the composite principle which ever took the water. Unlike most Royal yachts, she is used not merely for pleasure but also for scientific research, for the Prince of Monaco is well known for his contributions to the scientific knowledge of ocean depths and all that pertains thereto. The expeditions which he has organised, and most of which he has conducted in person, are invariably made on this yacht, which is splendidly equipped for the purpose. In order that she may be able to cover a large radius of action, she is fitted with an unusual coal capacity and can store in her bunkers sufficient to carry her 3700 miles. Under steam alone she can make 9 knots an hour, and with steam and sail combined she has been known to attain to nearly 12 knots an hour. The _Safa-el-bahr_, designed and constructed in 1894 by Messrs. A. and J. Inglis of Glasgow for his Highness the Khedive of Egypt, is also a steel-built two-decked yacht. She is schooner-rigged, and is fitted with three-stage expansion engines with cylinders 18 inches, 29 inches, and 48 inches in diameter, giving a piston stroke of 36 inches. These are supplied with steam at a pressure of 160 lb. from two boilers having a heating surface of 2300 square feet, and give an indicated horse-power of 1200, with a speed of 14·1 knots per hour. Her tonnage under yacht measurement is 677 tons. She has a length of 221 feet, breadth 27·1 feet, depth 17·3, with a draught of 12 feet.