This post was written by Amara L. Alexander, the 2019-20 Albert Einstein Distinguished Educator Fellow at the Library of Congress
Inventions can lead to new technologies, create new jobs, and improve quality of life. Use primary sources to help students compare and contrast the work of three inventors: Leo Wahl established a new barbering tool; Samuel F. B. Morse developed the telegraph; and Benjamin Franklin revolutionized sight with bifocal lenses.
Wahl helped to transform the barber industry with his patented design of an electric hair clipper. He noticed the need for barbers to improve their cutting techniques and tinkered until he developed the first electromagnetic motor powered hair clipper. Show students the ad and allow time for them to read the description. Based on the features described, what problems do they think Wahl was trying to solve?
Morse studied art in London, England, and he wished to communicate faster with his family across the sea. With his electrical telegraph, he observed the sparks from the electrical wiring and the length of time between the sparks. Those sparks could be transmitted into an electrical alphabet that he developed: Morse code. The dots and dashes transmitted over wires could relay messages to people that were miles apart. Covering the bottom half of the image, encourage students to focus on the diagram of the device. Survey the class to discover if students know the name and purpose. Ask questions as needed:
- What do you notice but can’t explain?
- What was the purpose of this device?
- What can you learn from examining this?
Allow students time to examine the image and record their responses. Next, reveal the bottom half of the page and invite students to think-pair-share. How does the new information change their thinking? Finally, display the the image of the service men using the telegraph and the deciphering Morse code and ask students what it suggests about uses of Morse’s inventions.
Benjamin Franklin has inventions credited to his name as well. A letter to friend George Whatley explains how bifocal lenses enabled Franklin to see his food more clearly and watch the facial expressions of those seated with him. Allow students to study the diagram and develop explanations of how the lenses worked.
Prompt students to think as inventors and focus on an object in the classroom, such as a door stopper. How might the item be improved? Offer students criteria for success and constraints on material, time, and cost. Guide them in planning and conducting an investigation based on their design model, and assess how well their inventions met the criteria and constraints of the design problem. Extend time for students to improve their model and retest.
For generations, innovators have used their imaginations to create new products to improve our daily lives. How can these historical examples spark innovation within your young inventors?