Steam-ships : The story of their development to the present day by R. A. Fletcher
introduction of the railway system inland. Between the two, however,
449 words | Chapter 2
there is the fundamental difference that the sea is a highway open
to all, while the land must be bought or hired of its owners; and
the result of this was that inland transportation, implying a huge
initial outlay on railroad construction, became the business of
wealthy companies, whereas any man was free to build a steamboat
and ply it where he would. The shipowner, moreover, has a further
advantage in his freedom to choose his route, because he is at liberty
to “follow trade”; but if, as has happened before now, the traffic
of a town decreases, owing to a change in, or the disappearance of,
its manufactures, the railway that serves it becomes proportionately
useless.
In another essential, the development of steam-transport on land and
sea provides a more striking contrast. The main features of George
Stephenson’s “Rocket” showed in 1830, in however crude a form as
regards detail and design, the leading principles of the modern
locomotive engine and boiler; but the history of the marine engine, as
of the steam-ship which it propels, has been one of radical change.
The earliest attempts were made, naturally enough, in the face of great
opposition. Every one will remember Stephenson’s famous retort, when
it was suggested to him that it would be awkward for his engine if a
cow got across the rails, that “it _would_ be very awkward--for the
cow”;--and at sea it was the rule for a long while to regard steam
merely as auxiliary to sails, to be used in calms. While ships were
still built of wood, and while the early engines consumed a great deal
of fuel in proportion to the distance covered, it was impossible to
carry enough coal for long voyages, and a large sail-area had still
to be provided. Progress was thus retarded until, in 1843, the great
engineer Brunel proved by the _Great Britain_ that the day of the
wooden ship had passed; and the next ten years were marked by the
substitution of iron for wood in shipbuilding.
Thenceforward the story of the steam-ship progressed decade by decade.
Between 1855 and 1865 paddle-wheels gave place to screw propellers,
and the need for engines of a higher speed, which the adoption of the
screw brought about, distinguished the following decade as that in
which the “compound engine” was evolved. Put shortly, “compounding”
means the using of the waste steam from one cylinder to do further
work in a second cylinder. The extension of this system to “triple
expansion,” whereby the exhaust steam is utilised in a third cylinder,
the introduction of twin screws, and the substitution of steel for
iron in hull-construction, were the chief innovations between 1875 and
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