The Cunard express steamer _Mauretania_, sister ship to the _Lusitania_, launched at Clydebank, was constructed on the Tyne by Messrs. Swan, Hunter, and Wigham Richardson, Ltd., who were already represented in the Cunard fleet by the _Ultonia_, _Ivernia_, and _Carpathia_. A description of the _Mauretania_ given by the builders and the Cunard Company states that the flat keel-plate is five feet wide and three and three-quarter inches thick, and forms a portion of the bottom of the ship. Associated with this flat keel is a vertical keel, five feet high and one inch thick, and to this vertebra are attached, directly or indirectly, the frames and beams which make up the skeleton. The double bottom is divided by this vertical keel and the transverse frames into compartments in which water-ballast may be taken. The tops of these tanks are carried well round the turn of the bilge, so that should the bilge keels be torn away and the hull pierced, the entering water would be confined between the inner and outer bottoms. As a further precaution towards securing insubmersibility, the lower deck is made completely water-tight. Below it are the orlop and lower orlop decks, and above are the main, upper, shelter, promenade, upper promenade, and boat decks--nine decks in all. Automatically closing water-tight doors are fitted in the bulkheads, and can be closed from the navigating bridge in a few seconds. The _Mauretania_ has 175 water-tight compartments, so that it is claimed for her that she is as unsinkable as a ship can be. “The steel plates which cover the ribs or framing of the vessel or are used for the decks, bulkheads, and casings, or in other ways, number 26,000, the largest being about 48 feet in length, and weighing from four to five tons. To secure these plates to each other and the structural framework of the ship, over 4,000,000 rivets have been used, aggregating in weight about 500 tons. The largest rivets are used in the keel-plate, and these are eight inches in length and weigh 2³⁄₄ lb. The main frames and beams placed end to end would extend thirty miles; the rudder, which has two sets of steering gear, both of which are below the water-line, weighs 65 tons, and the diameter of the rudder stock is 26 inches. The castings for the stem, stern-post, shaft bracket and rudder together weigh 280 tons. Her ground gear is, with that manufactured for her sister ship, the _Lusitania_, the strongest yet made. The three anchors each weigh ten tons, while the 1800 feet of cable is composed of 24-inch links, the iron in which is 3³⁄₄ inches in diameter and the weight of each link about 1¹⁄₂ cwts. This mighty harness has been vigorously tested, sample links and shackles emerging successfully from a test strain of 370 tons. “The principal measurements of the _Mauretania_ are: