The first steamer, built in 1829, was the _William Fawcett_, a small vessel of 206 gross tonnage, and but 60 horse-power. In 1842 the proprietors owned the _Hindostan_, of 2017 gross tonnage, and 520 horse-power. She was a paddle-wheel vessel, and opened the Indian Mail Service. The commencement of this service marks another stage in the history of steam navigation. About fifty years later the Company owned about half-a-hundred ships, two being of 8000 horse-power and 7000 tonnage. Some two years after the _Hindostan_ first steamed to India, Brunel’s _Great Britain_ was finished. She was a very remarkable vessel, and the wonder of her time. In the first place, she was built of iron, and, secondly, she was propelled by a screw, though at first it was intended that she should have paddle-wheels, and the engines for these wheels had been partly made. Barges and light vessels had been built of iron since about 1790, or earlier, and the Lairds of Birkenhead, among others, had built an iron vessel about 1829. It is said that the _Aglaia_ was the first iron steamer built on the Clyde in 1832. As for the screw-propeller, John Ericsson was successful with the _Francis B. Ogden_ in 1836, and three years later Sir Francis Pettit Smith clearly showed, in the vessel appropriately called the _Archimedes_, the value and the feasibility of the new system. Brunel, therefore, ever open to improvements, combined these two alterations in the _Great Britain_. It was in 1839, probably after Sir Pettit Smith’s success, that the change was made as regards the screw for this vessel, though the paddle-wheel engines had been begun. The superiority of the screw-propeller over the paddle-wheels are said to be these:—the engines occupy less room, and are lighter—two very important considerations. Then there is greater wear and tear on paddle-wheels, and consequently the screw vessels are less expensive. But most important of all, the screw being deep in the water, the vessel is much more suitable for ocean traffic. In the heaving billows of the sea one wheel may be buried deep on one side of the ship, and the other whirling round high in the air, and not propelling the vessel; whereas the screw, being always immersed, except possibly in severe pitching, is more constantly efficient for the whole of the vessel. Nevertheless, paddle-boats have their advantages. They need less water to work in, are started more easily, and stopped sooner. Further, it is said they are less liable to cause sea-sickness, as they do not roll so much. In a word, the difference seems to be this: paddle vessels are better suited as passenger boats on the shallower waters; screw vessels for deep sea and long distance voyages, though whether the adoption of twin-screws,—which it appears need not be immersed so deeply in the water as one screw,—will bring screw vessels into use on shallower waters remains to be seen.