Primary Sources in Science Classrooms: Communicating between Continents with Cables and Code

This post was written by Trey Smith, the Library of Congress 2015-16 Science Teacher in Residence as a follow-up to a feature in the February issue of NSTA’s The Science Teacher magazine.

Modern communication systems allow people to share images and sound around the world in real time. Previously, messages between continents traveled by boat. That changed in 1858 with the installation of an underwater cable that carried coded electrical pulses between North America and Europe.

Introduce a lesson or unit on electricity, engineering, or computer science using historical primary sources that describe the first transatlantic telegraph.

• A festival song and a ballad called the “Age of Progress” both celebrate the Atlantic telegraph.
• A newspaper illustration includes the text of messages sent between England and the United States.
• A print shows two men grasping hands across the Atlantic with cable-laying ships in the background.

To help students learn about the event, encourage them to analyze the documents and consider:

• what happened and who was involved,
• the purpose of and audience for each text,
• how the authors of each text wove together scientific ideas with descriptive and poetic language, and
• the political and social implications of the scientific and engineering achievement.

Students might also consider what poets, artists, and songwriters would say about some of our modern communication technologies.

Poems, prints, and songs were not the only records of the 1858 event. A newspaper article in the Weekly North Carolina Standard includes log notes from Cyrus West Field. Field, a businessman who created the Atlantic Telegraph Company, traveled on the Niagara ship that laid half of the cable. Students studying electricity and insulators might pay close attention to these log entries.

Students might also compare Field’s notes to subsequent efforts to install new cables after the first one failed. Share with students the 1865 chart by George Washington Bacon called The Atlantic Telegraph.

Bacon’s chart includes:

• a map of the locations of underwater cables,
• cross section diagrams detailing the materials used in the construction of the cables,
• diagrams of a telegraph and Morse code, and
• a timeline of the engineering challenges and solutions associated with laying cables on the ocean floor.

When students analyze the historical documents, they might wonder:

• Do we still use underwater cables to carry communications?
• What has replaced Morse code as the dominant coded language?
• Which materials are used in today’s wired and wireless communication technologies? And what are the properties of those materials that make them so useful?

Finally, teachers interested in engaging students in an engineering project might provide students with materials to make their own working telegraphs. Begin with this document that shows the telegraph and symbols used in Morse code and dig into Samuel Morse’s papers related to the invention of the telegraph.

How might students benefit from studying and building communication technologies from 150 years ago?