1706 – 1790

Benjamin Franklin was one of the five men who drafted the Declaration of Independence of 1776. He was also a prolific scientist.

Benjamin Franklin had a rare genius. Unlike most of the scientists chronicled on this site who were known for their outstanding talents and contributions to science, the American Franklin was brilliant in a wide range of arenas. In a five-year period between 1747 and 1752, he contributed more to science than most scientists would achieve in a lifetime of dedicated study. Yet, during other periods of his life, he operated in, and conquered, completely different fields. He was a master printer and publisher, a successful journalist and satirist, an inventor, a world-famous ambassador and, probably most notably of all, a politician at a vital time in American history. Indeed, Franklin was one of the five separate signatories of the Declaration of Independence from Great Britain in 1776 and was a key participant in the later drafting of the American Constitution.

. Studying Electricity

Franklin does, however, merit an entirely separate entry for his achievements in physics alone – he was a pioneer in understanding the properties and potential benefits of electricity. Although the phenomenon of electricity had been noted since the time of the ancients, very little was known about it from a scientific perspective, and many considered the extent of its usefulness to be limited to ‘magic’ tricks. At around the age of forty, Franklin became fascinated by electricity and began to experiment with it, quickly realising it was a subject worthy of scientific study and research in its own right. So, he sold his printing interests and dedicated himself for the next five years to understanding it.

. Flying a Kite

Although Franklin wrongly believed electricity was a single ‘fluid’ (this was an advance on earlier theories which posited the idea of two different fluids), he perceived this fluid to somehow consist of moving particles, now understood to be electrons. More importantly, he undertook important studies involving electrical charge and introduced the terms ‘positive’ and ‘negative’ in explaining the way substances could be attracted to or repelled by each other according to the nature of their charge. He also believed these charges ultimately cancelled each other out so that if something lost electrical charge, another substance would instantly gain the amount being cast away. His work on electricity reached its peak in his now famous kite experiment of 1752. Believing lightning to be a form of electricity, and in order to prove it, Franklin launched a kite into a thunderstorm on a long piece of conducting string. Tying the end of the string to a capacitor, he was vindicated when lightning did indeed charge it, proving the existence of its electrical properties. From these results and realising the potential of a device that could deflect the harmful effects of lightning strikes away from buildings and property, he developed the lightning conductor.

Franklin had also published his text Experiments and Observations on Electricity, made at Philadelphia in America in 1751, which went on to inspire future scientists in the study and development of the uses of electricity.

. A Prolific Inventor

From 1753 the time Franklin dedicated to science reduced dramatically due to his taking up a new post as deputy postmaster general and, later, political and ambassadorial roles. He did, however, leave a legacy of other inventions from the wide range of experiments conducted throughout his life, including: an iron furnace ‘Franklin’ stove (still in use today), bifocal spectacles, the street lamp, the rocking chair, the harmonica, an odometer and watertight bulkheads for ships. Franklin also came up with the idea of Daylight Saving Time and was the first to charter the Gulf Stream from observations made by sailors.

A man of many talents, Benjamin Franklin was a successful inventor, politician, printer, oceanographer, ambassador, journalist and, of course, scientist.

. The Legacy of Benjamin Franklin

Franklin’s legacy, in addition to the many inventions such as lightning conductors, bifocal lenses and street lamps, was one of learning. He established one of the first public libraries, as well as one of the first universities: Pennsylvania, in America.

On a broader societal level, he established the modern postal system, set up police and fire fighting departments and established the Democratic Party.

He certainly lived up to his own quotation, ‘If you would not be forgotten as soon as you are dead and rotten, either write things worth reading, or do things worth the writing.’