But, let's get on with our power system. The teakettle representing the boiler is not a very
efficient generator of steam. Let's see if we cannot design a better one. Look at the sketch
on the next page. Here we have a boiler consisting of two steel drums connected by a
number of steel tubes, and arranged in a furnace so that the hot gases have to pass through
the bank of tubes on their way to the stack. The total surface of the tubes is large, making it
possible to absorb a great deal of heat. The steam bubbles formed in the tubes rise to the
upper drum (called the steam drum) where the steam collects before it flows into the pipe
leading to the turbine