Snell’s illustration of sound waves, Science Teaching Collection

Ebenezer Snell was the professor of physics at Amherst College and a central figure in science education in 19th century America. In the 1850s he developed a series of wave models that he used in his teaching. The models were very popular and by 1860 five of them were being produced commercially for use in schools and academies.

Source: Steven Turner; Curator, Physical Sciences, National Museum of American History, Smithsonian Institution. 

Picture: Steven Turner

http://americanhistory.si.edu/science/