1900, there were 9000 cars on the road. Just 60 years later, there were
95 million, all powered by petrol-driven internal combustion engines that
were faster, lighter and more powerful than the previous steam engines.
The internal combustion engine transformed air and sea travel as well, in
turn, dramatically shaping the course of the 20th century.
However, despite all the
speed and excitement of new forms of transport, it was mostly the industralized
nations of North America and Europe that benefited from it. For example,
in 1914, the average person in USA travelled 2500km (1600 miles), each
year, mostly on foot, while fifty years later, they went twice as far
each month, mainly by car. In the less developed countries, most still
did not have cars in 1960. Many still use animal for transportation of
people and goods.
MOBILITY ON LAND
Cars gave their owners the freedom of convenient travel. With their new
mobility, car owners could choose to live further away from their workplaces.
People who could not afford cars relied mainly on public transport. Railway
thrived in the early years of the 20th century, while efficient trams
and motor-buses on city streets put horse-drawn vehicles out of business.
On water, the diesel engine - a type of internal
combustion engine - was put to work on samller vessels, while bigger
ships were driven by steam turbines. The age of large sailign ships was
virtually at an end. In the years before World War II, liners grew in
comfort, speed and size, carrying hundreds of wealthy travellers in conditions
of grandeur and elegance. In the age of the luxury liner, the journey
was more than half the fun (for the rich).
Growing interest in leisure activities, such as water-skiing and
surfing promoted improvements in transport technology. It helped the development
of tougher and longer lasting materials, that were needed to make skis
and surfboards. Similarly, road racing helped car makers find out the
reliability and sturdiness of vehicle parts.
CARS FOR THE MASSES
Early, hand-made cars such as Roll-Royce's Silver Ghost were extraordinarily
costly. A new method of manufacturing, called "mass production" revolutionised
the development of the car. Cars mass-produced on the assembly lines in
factories, such as the famous Ford Model
T (1908-1930s) and the Volkswagen "Beetle" (1936-1980s), became affordable
to the common people. Improved roads and specially built inter-city motorways
made car travel more convenient then ever.
Wings are the secret to powered flight: the top surface of an aircraft
wing bulges upwards, with a nearly flat underside.
Air pressure tends to be higher beneath the wing as it travels forward,
giving the wings an upward "lift", that keeps the aircraft aloft.
Otto invented the internal combustion engine in 1888. In most internal
combustion engines, a spark ignites a mixture of air and petrol vapour
inside a cylinder. The resulting explosion pushes out a piston, whose
motion is used to rotate a crank that turns the engine. Most engines have
at least four cylinders that fire in turn.
After 1900, petroleum oil began replacing coal as transport's main energy
source. Fuels made from this thick black liquid pack maximum energy into
a minimum of space and weight. Oil is the decomposed remains of ancient
marine creatures, and is found underground, so it has to be pumped up
to the surface. Oil wells were first established in the USA and later
in Russia, the Middle East and other parts of the world where there are
Electric-powered public transport saved the fast-growing cities of the
early 20th century from chaos. Electric trams and trains, taking power
from an overhead cable or extra ground rail, had ggood acceleration and
could stop quickly. Electricity is efficient and pollution-free, but messy
fuels such as coal and oil were still being burned in power stations to