Assassination of Garfield
James A. Garfield (left) and Alexander Graham Bell (above)
Lesson Overview
The Assassination of Garfield story invites learners to experience how some STEM professionals must work quickly and under unusual circumstances to solve problems. Using knowledge of the telephone and its components, Bell and his colleagues invent devices to try to find the bullet in Garfield's back. In this LA STEM Story, students are invited to join Bell to recreate the telegraph, microphone, speaker, and ultimately a metal detector.
1. LA STEM Story: The Assassination of the President Story
When the nation experienced the assassination of President Abraham Lincoln in 1865, the act was considered an outcome of the bitter Civil War. When the newly elected President Garfield was shot in 1881, the nation was in shock. How could such a terrible thing happen when the nation was at peace? Who would do such a thing? Among those deeply affected by the tragedy was Alexander Graham Bell. On hearing the news that the president had been shot, but that the bullet could not be located, Bell's STEM brain went into action. How could he use what he knew to help design a device for finding the lead lodged deep in the lower back of the president? It is important to engage students in the story in order to spark their interest in the unit. Prompt students to ask questions and to note interesting information. Read the entire story with primary source material included at Assassination Story. Read a shorter version material here.
You can use questions such as:
"What do you find interesting about the story?"
"What would you like to know more about?"
"What questions do you have from reading the story?"
For more information about how students can read the story go to Reading LA STEM Stories.
Students should record observations or questions in a notebook. See directions for the STEM Notebook here.
What did Bell know, and how was he able to make a metal detector from that knowledge?
2. Choose any or all of the following exploration options:
A. Build a working telegraph system. Bell had experience with a system that had been around for many years. Students re-create a telegraph system with simple materials to send code from one station to another.
B. Make an interrupter. Bell experimented with the telegraph sender and receiver to modify the receiver to work independently as a buzzer or interrupter. Students make an interrupter by modifying their telegraph receiver.
C. Make a speaker. As Bell developed the idea of the telephone he had to convert electrical pulses into sound. Students construct a simple speaker from simple materials and test it on various electrical sources.
D. Make a harmonic telegraph. By manipulating the sender, Bell discovered that he could send tones over the telegraph wires. Students construct a simple harmonic telegraph and receive the tones over a speaker.
E. Make a microphone. Bell's most difficult challenge was converting sound waves ino electrical pulses. In this experiment, students use a pencil lead resting on metal as a microphone.
F. Make a telephone system. After many experiments and adjustments, Bell invented a working telephone. Students use speakers and batteries to make a working system.
G. Recreate Bell's Metal Detector. Students make observations about a portion of a telephone circuit and then experiment with the effects of metal placed in the field of a coil.
3. STEM Challenge for Students
Using his background and knowledge from his experience with the telegraph, interrupter, speaker, and telephone, Bell deduced the possibility of a metal detector. In this STEM challenge, students will take the components from what they have made to repeat these experiments and search for metal and listen for differences between types of metals they test.