Bifocals: Franklin was both nearsighted and farsighted, and had to alternate between two pairs of glasses depending on what he was trying to see. As a solution to his frustrating problem, Franklin had the lenses from his two pairs of glasses cut in half and reassembled in one frame with the lenses for distance on top and the lenses for reading on the bottom. Franklin's idea for bifocals is still the basic model used today.
Franklin stove: Fireplaces heated most homes in colonial America. Fireplaces were inefficient heat sources because of the large amount of wood needed and were dangerous because sparks could easily ignite a fire elsewhere in the house. Franklin invented an iron furnace stove that used less wood, radiated more warmth through the heated iron, and was safer because the fire was better contained. Franklin stoves are still in use in some homes today.
Lightning Rod: Franklin's investigations into the nature of electricity led him to this simple invention with a powerful purpose. By mounting a pointed iron rod on the highest point of a building, Franklin discovered that it would attract lightning flashes and channel the electrical current to the ground, thereby preventing other parts of the building from catching on fire. Lightning rods can be found on buildings today, although they are usually made of copper.
Odometer: While serving as postmaster for the northern colonies, Franklin had to establish mail routes. In order to measure distances, he invented an odometer, which could be attached to the axle of his carriage wheels to count the rotations. Odometers are standard instruments in modern vehicles.