This guest post is from the Library of Congress Teacher in Residence, Earnestine Sweeting.
It didn’t occur to me until recently that my math lesson was missing a primary source. After a simple search for “tetrahedron” or “tetrahedral kites” on the Library of Congress Web site, I was fascinated to find primary sources that could have enriched my geometry and measurement lessons.
To strengthen my fifth grade students’ skills in geometric fundamentals, I would schedule a few math periods for them to build a tetrahedron, which is a three-dimensional triangular figure. What I like most about this project is that it provides a challenge for students who crave multi-step problems to solve while it offers hands-on appeal for all. Tetrahedra are combined to design a tetrahedral kite. After some construction work with drinking straws, string, and tissue paper–plus a little will-this-fly skepticism–my students went out on a breezy day to see their tetrahedral kites take flight.
I was amazed to discover the use of tetrahedral units in the construction of kites found in Alexander Graham Bell’s Family Papers were the same principles I used with my students. Little did I know that Bell used the tetrahedral principle by combining triangular units to build very large kite structures. After reflecting on my students’ skepticism, I wonder if their reaction would have been different had I shared Bell’s theory of very large kite structures made out of light materials.
In Bell’s papers, he insisted that the lack of interest in kites arose from the false idea that a kite could only be a plaything or toy. I encouraged my students to refer to the structure only as a tetrahedron, rather than a kite. My rationale was not only to build their vocabulary, but also to emphasize the academic value in engaging in such a project. This 1904 Washington Times article explains that Bell had long been interested in the flying machine problem, and became convinced that a successful kite will also make a successful flying machine.
- After reading this 1903 St. Louis Republic article, students can consider the process Bell used to find solutions to the problems he faced. Encourage students to compare and contrast how Bell’s problems were similar to those they’ve encountered in their own real-world endeavors–or those of others they might know. How did Bell’s experiences contribute to the overall success of his flying machine?
- Ask students to think of a classmate or a friend who would benefit from reading Bell’s papers and explain the reasons for making the recommendation. What can we learn from Bell’s argument to think differently about something once considered to have no practical use?
For additional resources, go to With Wings as Eagles: From Flight to Fantasy.
Share the discoveries you’ve made when using primary sources to add depth or historic achievements to your math or science lessons.