Electricity:
Franklin experimented extensively with electricity, determining that there are two types of electricity, positive and negative. In 1752, his experiments with a kite in a thunderstorm (never do this, many people have died trying it!) led to the development of the lightning rod.

Inventions and Innovations:
Franklin started the first circulating library in the colonies in 1731. He had been a writer himself since an early age, ran a printing press, and wrote and published a newspaper (the Pennsylvania Gazette) and the very popular "Poor Richard's Almanack" (published annually from 1733 to 1758). [An almanac is a book that is published yearly; it contains useful information, including a calendar, weather information, times of sunrise and sunset, tides, moon phases, recipes, and other interesting facts.] Franklin added memorable aphorisms (useful sayings) to his almanac, like, "A penny saved is a penny earned," "In this world, nothing is certain but death and taxes," and "An ounce of prevention is worth a pound of cure."

Franklin invented bifocal glasses (glasses for people who are both nearsighted and farsighted, like Franklin in his later life). Tired of switching between two pairs of glasses, Franklin cut the lenses of each pair of glasses horizontally, making a single pair of glasses that focused at both near regions (the bottom half of the lenses) and far regions (the top half of the lenses).

He also invented the Franklin stove (an efficient, cast-iron furnace located in the middle of a room), swim fins, the odometer (mileage recorder), the ladder chair (a chair that converts into a library ladder), the glass (h)armonica (a musical instrument composed of rotating glass cylinders), and the first medical catheter. Active in his community, Franklin started the first American fire company, the first American street-cleaning department, the first city hospital, the school that would later become the University of Pennsylvania, and reorganized the American postal system.

Daylight Saving Time:
The idea of Daylight Saving Time (DST) was first proposed by Benjamin Franklin in 1784 in an essay called "An Economical Project," which he wrote during time he spent in France (Franklin was the first US ambassador to France, serving from 1776 until 1885).