ABSTRACT
Sir William Armstrong has applied hydraulic power to cranes and other machines in combination with chains and pulleys. A special feature of Sir W. Armstrong’s hydraulic crane is the arrangement by which the engines are made to be always storing up power by forcing water into the vessel, called the “accumulator.” Hydraulic power has also been used for launching ships, and the launch of the Great Eastern is a memorable instance; for the great ship stuck fast, and it was only by the application of an immense pressure, exerted by hydraulic apparatus, that she could be induced to take to the water. Hydraulic power has been used not only for graving docks, but also for dragging ships out of the water up an inclined plane. A famous example of the application of hydraulic power was the raising of the great tubes of the Britannia Bridge.
