Of all the experiments and innovations in Benjamin Franklin's scientific career, the most famous must be his study of lightning and subsequent kite experiment. Before Benjamin Franklin, lightning and its properties were not fully understood. To begin with, understanding of electricity was still relatively primitive. Not only did Franklin prove that lightning was indeed electrical, he also helped advance the concept of positive and negative charges which had previously been considered completely different forms of "electrical fluid." Franklin's kite experiment became so well-known and admired that he earned himself an invitation to meet the King of France and explain his vision of future possibilities for electricity in innovation. Franklin inspired many imitators as well as critics who unwittingly proved his theory through their own failed experiments. Franklin's discovery of the concept of charge conservation advanced the idea of electric technology. As much as we now rely on electricity for the convenience of our daily lives, Franklin was painfully aware that he lived in a time that was simply too early for the widespread use of electrical machines and systems.
The first invention born directly from his kite experiment would be the lightning rod Ben Franklin designed for protecting buildings from fire during electrical storms. With the lightning rod, Benjamin Franklin utilized the concept of conduction of electrical currents and grounding to craft a series of metal poles that would carry the electricity from a lightning strike down from the roof of the building safely into the ground. Because most contemporary buildings were made of wood, the threat of fire from a lightning bolt was a realistic and recurring one. Soon after his invention was announced, Franklin demonstrated the effectiveness of his lightning rods on his own home in Philadelphia. One of the first lightning rods elsewhere was installed on the Pennsylvania State House, the seat of government in Pennsylvania and the future site of the Continental Congress. Today, lightning rods are still a necessary addition to many tall buildings and serve much the same purpose as the originals. The history of Benjamin Franklin and the lightning rod also demonstrates his sense of community service as he refused to take out a patent on any of his inventions and only wished that people would find joy and utility in his crafty and sensible innovations.
Immediately after word of Franklin's kite experiment spread, there were many imitators and not all of them were completely successful. A German physicist living in Russia, one Professor Georg Wilhelm Richmann, managed to electrocute himself while enticing sparks from the clouds during a lightning storm. Accounts of Franklin's experiment hint that he was acutely aware of the danger and prepared the experiment so that the kite holder would not be in the path of electrical conduction. Actually, it is likely the Franklin simply gathered an electrical charge in the kite and conserved it for transfer into a leiden jar, thus proving that the lightning consisted of the same force as the electricity that charged the old glass battery.