The most mundane things that you use every day (think post it notes, rubber bands, concrete) often have fascinating stories behind them.
In fact, people often only notice how something's designed when it goes wrong. But the process of discovery, testing and prototyping anything, no matter how ordinary, is full of pitfalls and the occasional exhilarating breakthrough.
Spitfire 1936. Reginald J. Mitchell
Reginald Joseph Mitchell died in 1937 and never saw his most famous design, the Supermarine Spitfire, fulfil its potential. Testament to the soundness of Mitchell's design was the fact that the Spitfire would be continually improved from its first test flight in 1936 through to the end of its service in the early 1950s.
One of the keys to the Spitfire's longevity was its elliptical wing. The rounded shape of the wing ends and thin cross-section reduced drag, allowing a higher top speed than many other fighters of the day. It was also incredibly manoeuvrable, able to climb to higher altitudes than its contemporaries.
24 different versions of the Spitfire were designed during its life. It was the only Allied fighter to be in production during the outbreak of World War 2 and still be in production at the end. More than 20,000 were built in total, more than any other Allied design.
Steam Engine