2. Benjamin Franklin Scientist and Inventor By: Lauren Obermaier ETE 100 Section 02 November 15 th 2009

3. Portrait of Benjamin Franklin Franklin’s favorite portrait of himself. It shows him as a learned scientist and inventor. Look closely, lightning can be seen through the window. Lightning was a main component of Franklin’s most famous discoveries. Here are some fun facts about Franklin before we get started! (Read the discover light bulbs.) Benjamin Franklin…In His Own Words. Library of Congress. U.S. Govt. 15 November 2009.

4. The Franklin Stove Franklin drew this model of the stove that he created. It works by using iron plates to control the airflow inside the stove. It made the stove much more practical. This made it very popular because less heat was lost and not nearly as much wood was needed. It was described by many as giving off twice the heat of a normal fire place and a third of the wood consumed. Benjamin Franklin…In His Own Words. Library of Congress. U.S. Govt. 15 November 2009.

5. Franklin’s Design for Bifocals Benjamin Franklin is credited with the invention of bifocals in the early 1760’s. They were first designed with the most convex lenses, for very close viewing, in the lower half of the frame At the higher half of the frame, less convex lenses were used for farther viewing. They were constructed with the two different lenses inserted into the same frame, making them very hard to build and keep together. Benjamin Franklin…In His Own Words. Library of Congress. U.S. Govt. 15 November 2009.

6. Franklin’s Experiments in Electricity From 1747 to 1750, Franklin composed a series of letters describing many of his experiments on electricity. In the letters: He introduced his new theory of positive and negative charges that occur in lightning. He proposed that lightning had electric capabilities that could be harnessed for the good of humans.

7. Franklin’s Experiments in Electricity Continued His letters were published in 1751 by Peter Collinson, who was the President of the Royal Society. It was because or these experiments that Franklin became a well known and regarded scientist. In 1753, he received the Copley Medal from the Royal Society for his input on lightning and electricity.

8. Franklin’s Mapping of the Gulf Stream Franklin became interested in mapping the Gulf Stream. He found it intriguing that the trip from North America to England was much shorter than the returning trip was. Benjamin Franklin…In His Own Words. Library of Congress. U.S. Govt. 15 November 2009.

9. Franklin’s Mapping of the Gulf Stream Continued Franklin consulted his cousin, Nantucket Sea Captain, Timothy Folger for more information. He asked him for the dimensions of the route. Franklin discovered that if the wrong route was taken then the trip would become substantially longer. In 1786, he published the map and directions to avoid the route in the Transactions of the American Philosophical Society. Systematic research to test the validity was not done until 1845.

10. Franklin’s Attempts at Curing the Common Cold Benjamin was always concerned with using science in a practical sense to help people. He wrote a paper called, “Definition of a Cold” in which he discussed some ways to avoid getting the common cold. He believed that:  Exercise  Bathing  Moderation in food and drink Could help people to stay healthy.

11. Franklin and His Beliefs on the Aurora Borealis Franklin became very interested in the “Northern Lights” on his trips across the North Atlantic to England. On these trips he made many observations and theories: He believed that the phenomena was due to the concentration of the electrical charges in the area. He also believed that the lights were intensified by snow and other moisture. From all of this he concluded that the overcharging of the particles caused a release of electrical illumination into the air in form of the lights. Teacher’s Notes: Auroras or “Northern Lights” are the result of the emissions of many nitrogen and oxygen atoms returning from an excited to normal state. The atoms first become ionized by colliding into wind particles that are funneled down the Earth’s magnetic field lines. They create beautiful, colorful lights in the night sky.

12. Franklin’s Armonica The Armonica is an instrument composed of graduated glass discs on a spindle laid down horizontal in a case. To make it work, one would revolve the spindle by a foot treadle. Finally, they would touch wet fingers to the revolving glasses. This created beautiful bell-like tones. It became so popular in Europe that even Mozart and Beethoven composed music for it. Listen to the Armonica, one of Franklin’s favorite inventions! Benjamin Franklin…In His Own Words. Library of Congress. U.S. Govt. 15 November 2009.

13. References “Benjamin Franklin…In His Own Words.” (2006). Retrieved November 15 th, 2009, from http://www.loc.gov/exhibits/treasures/franklin- scientist.html Zeitler, W. (2007). Dance of the Sugar Plum Fairy. From The Nutcracker [Musical]. Retrieved November 15 th, 2009, from http://www.youtube.com/watch?v=eQemvyyJ--g