Armonica:
"Of all my inventions, the glass armonica has given me the greatest personal satisfaction."
Benjamin Franklin was inspired to create his own version of the armonica after listening to a concert of Handel's Water Music which was played on tuned wine glasses.
Benjamin Franklin's armonica, created in 1761, was smaller than the originals and did not require water tuning. Benjamin Franklin's design used glasses that were blown in the proper size and thickness which created the proper pitch without having to be filled with water. The glasses were nested in each other which made the instrument more compact and playable. The glasses were mounted on a spindle which was turned by a foot treadle.
His armonica won popularity in England and on the Continent. Beethoven and Mozart composed music for it. Benjamin Franklin, an avid musician, kept the armonica in the blue room on the third floor of his house. He enjoyed playing armonica/harpsicord duets with his daughter Sally and bringing the armonica to get togethers at his friends' homes.
Franklin Stove:
Fireplaces were the main source of heat for homes in the 18th century. Most fireplaces of the day were very inefficient. They produced a lot of smoke and most of the heat that was generated went right out the chimney. Sparks in the home were of great concern because they could cause a fire that would quickly destroy the homes, which were constructed mainly with wood.
Benjamin Franklin developed a new style of stove with a hoodlike enclosure in the front and an airbox in the rear. The new stove and reconfiguration of the flues allowed for a more efficient fire, one that used one quarter as much wood and generated twice as much heat. When offered a patent for the fireplace's design, Benjamin Franklin turned it down. He did not want to make a profit. He wanted all people to benefit from his invention.
Lightning Rod:
In 1752, Benjamin Franklin conducted his famous kite flying experiments and proved that lightning is electricity. During the 1700s lightning was a major cause of fires. Many buildings caught on fire when struck by lightning and kept burning because they were built mainly of wood.
Benjamin Franklin wanted his experiment to be practical, so he developed the lightning rod. A tall rod is attached to the outside wall of the house. One end of the rod points up into the sky; the other end is connected to a cable, which stretches down the side of the house to the ground. The end of the cable is then buried at least ten feet underground. The rod attracts the lightning and sends the charge into the ground, which helps to decrease the amount of fires.