Besides his role as a diplomat, writer, printer and publisher, Benjamin Franklin was also a prominent scientist and inventor. Many people are familiar with his kite experiment that proved the electrical nature of lightning, but not everyone is aware that Franklin helped chart the Gulf Stream, tracked the population growth of North America, and established the principle of cooling by evaporation. Benjamin Franklin experiments on electricity also included the discovery of conservation of charge and the first time that the two forms of electric charge would be labeled "positive" and "negative" instead of "vitreous" and "resinous" as they had been previously. He provided heavy influence on a number of scientific subjects including meteorology and geo-engineering. His observations on difference between the prevailing wind and the direction of cloud movement are still relevant to meteorology and his study of the causal relation of volcanic eruption and a harsh winter are still relevant to geo-engineering. Benjamin Franklin as a scientist had just as much if not greater influence than his role as a diplomat. His experiments were revolutionary and his inventions were sensible and useful.
The most famous of Ben Franklin experiments is still certainly his foray into a lightning storm with a wet kite. Laying out his plans in 1750, it was not until two years later that Franklin would find the conditions and timing necessary to prove his hypothesis. With a copper key tied to the kite, Franklin stood under the pouring rain in a June storm and successfully drew sparks out of the clouds. By conserving the charge in the key and returning home to conduct it into another vessel, Franklin proved that lightning was indeed electric. Although a French scientist by the name of Thomas-Francois Dalibard had done the same experiment using a 40 foot tall iron rod a month before, it was Franklin who received credit for devising the plan and proving his hypothesis. The discovery made him famous throughout the European world and he was invited to meet the King of France to explain the possibilities of electricity in future innovation. Although Franklin published instructions for duplicating his experiment safely, a number of imitators electrocuted themselves.
For Benjamin Franklin, science was more than just understanding nature, he also wanted to put his discoveries to good use. After the kite experiment, Franklin devised an invention that is ubiquitous today: the lightning rod. He tested the first lightning rod on his own home and proved that a sharpened pole on the roof of the building could draw a current of electricity silently down a wire and safely into the ground. Soon, the first public lightning rods were installed on the Academy of Philadelphia (later known as the University of Pennsylvania) and the Pennsylvania State House (soon to become Independence Hall). Ben Franklin, scientist and inventor, also crafted a cast-iron stove with a hollow baffle and introverted flue in the rear to draw smoke out of the house while still retaining more heat. Like all his inventions, Franklin never took out a patent as he believed that he had enjoyed the inventions of others freely and would only wish to give back to the community.