[Illustration: [_By courtesy the Cunard Line._ MODERN NAVIGATION. Captain Sir James Charles, K.B.E., C.B., R.D., R.N.R., and officers of the “Aquitania” taking the sun’s altitude.] _Olympic_ came out as the world’s biggest ship, and she is one of the fastest. On one occasion coming up Channel she recently touched 27·82 knots for a brief spell, but her best average speed for a whole voyage is 22·55 knots, and her quickest passage is five days, nineteen hours, 12 minutes. For the consideration of the big German liners who were competing with these efforts the reader is referred to the chapter dealing with the rise and fall of the German Mercantile Marine, but the next British mammoth was the _Aquitania_, which was put into the Cunard service just before the war began. She is over 900 feet long, she can steam at a little more than twenty-three knots, and her best passage, east-bound, has been five days, nineteen hours, forty-one minutes. Her gross tonnage is 47,000. I watched _Aquitania_ being built, from the time when she was a mere mass of steel, and finally saw her take the water in the Clyde, and walked all over her half an hour before this impressive event took place. She was barely ready for her intended work than she was turned into an armed merchant cruiser and joined Admiral Phipps Hornby’s Cruiser Squadron on the Atlantic trade route. But it was rather like putting a race-horse to do the work of a cart-horse. _Aquitania_ was then, like other merchantmen, coal-burning, and her endurance was only six days, for she was built for the purpose of rushing across the Atlantic, then filling up and returning as fast as she could. She was thus not suitable for patrolling, and after colliding with a Leyland liner, whilst under the command of a naval officer, _Aquitania_ terminated her engagement as a warship, and then did far more useful work during the time of hostilities, until she again took up her peaceable service. This was the last British-built merchant ship to be constructed of mammoth size that is still afloat. The White Star _Homeric_, which joined the Atlantic service in the spring of 1922, is an ex-German vessel. This ship is neither as big nor as fast as _Aquitania_, but she is the largest twin-screw steamer afloat. Her best average speed for a whole trip is 18·69 knots, and her best voyage is six days, nineteen hours, twenty-two minutes. But the slump which followed the war and the depression which came over the shipping trade made it undesirable to lay down any more of these leviathans for the present, and there was still another reason.