factories where the raw materials of these basic industries are worked
into finished products. Its value for showing scenery, too, is fully
utilized here. Many of the states and foreign countries employ it. Even
faraway Siam uses it to instruct the Occident concerning her resources
and people. Counting those in the state and foreign buildings,
seventy-seven free moving-picture halls are to be found within the
Exposition. Their efficiency is indicated by the crowds that throng them
daily.

The Palace of Machinery holds three lessons for the observer. It shows
not only the state of man's invention at the present moment, the
increasing displacement of coal by hydroelectric plants and liquid
fuels, but what is perhaps more significant, the changing direction of
invention toward devices for human betterment. The Diesel oil engine and
multitudes of electrical machines stand for the latest word in
mechanical invention. The Diesel again, with a host of other internal
combustion engines, the electric motors and waterpower plants, and the
absence of steam machines, bear witness to the downfall of steam. But
the great space given to safety devices, to labor-saving machines, to
road-making machinery, and to mechanical devices for increasing the
comfort of country life, are evidence of the part machinery is coming to
play in the task of making life more livable. As an exhibition of modern
mechanical invention, Machinery Hall is unique, as all this Exposition
is unique. There is almost nothing in it that is not the product of the
last ten years; it actually represents construction of the last two
years. Indeed, the wholly contemporary nature of the exhibits leaves the
visitor without visible means of comparison.

As at the Centennial Exhibition in 1876, a prime mover is the central
figure in the building. There it was the immense Corliss steam engine.