Some years before--indeed, about the time that Smith took out his patent--Captain Ericsson, the Swede, invented a screw propeller. Smith took out his patent in May, 1836; and Ericsson in the following July. Ericsson was a born inventor. While a boy in Sweden, he made saw mills and pumping engines, with tools invented by himself. He learnt to draw, and his mechanical career began. When only twelve years old, he was appointed a cadet in the Swedish corps of mechanical engineers, and in the following year he was put in charge of a section of the Gotha Ship Canal, then under construction. Arrived at manhood, Ericsson went over to England, the great centre of mechanical industry. He was then twenty-three years old. He entered into partnership with John Braithwaite, and with him constructed the Novelty, which took part in the locomotive competition at Rainhill on the 6th October, 1829. The prize was awarded to Stephenson's Rocket on the 14th; but it was acknowledged by The Times of the day that the Novelty was Stephenson's sharpest competitor. Ericsson had a wonderfully inventive brain, a determined purpose, and a great capacity for work. When a want was felt, he was immediately ready with an invention. The records of the Patent Office show his incessant activity. He invented pumping engines, steam engines, fire engines, and caloric engines. His first patent for a "reciprocating propeller" was taken out in October 1834. To exhibit its action, he had a small boat constructed of only about two feet long. It was propelled by means of a screw; and was shown at work in a circular bath in London. It performed its voyage round the basin at the rate of about three miles an hour. His patent for a "spiral propeller," was taken out in July 1836. This was the invention, to exhibit which he had a vessel constructed, of about 40 feet long, with two propellers, each of 5 feet 3 inches diameter. This boat, the Francis B. Ogden, proved extremely successful. She moved at a speed of about ten miles an hour. She was able to tow vessels of 140 tons burthen at the rate of seven miles an hour. Perceiving the peculiar and admirable fitness of the screw-propeller for ships of war, Ericsson invited the Lords of the Admiralty to take an excursion in tow of his experimental boat. "My Lords" consented; and the Admiralty barge contained on this occasion, Sir Charles Adam, senior Lord, Sir William Symonds, surveyor, Sir Edward Parry, of Polar fame, Captain Beaufort, hydrographer, and other men of celebrity. This distinguished company embarked at Somerset House, and the little steamer, with her precious charge, proceeded down the river to Limehouse at the rate of about ten miles an hour. After visiting the steam-engine manufactory of Messrs. Seawood, where their Lordships' favourite apparatus, the Morgan paddle-wheel, was in course of construction, they re-embarked, and returned in safety to Somerset House.