Conversation so far:
What were Alexander Graham Bell's later inventions?
Alexander Graham Bell's later inventions included 14 for the telephone and telegraph, four for the photophone, one for the phonograph, five for aerial vehicles, four for hydroairplanes, and two for selenium cells.
What ideas did Alexander Graham Bell have regarding teaching speech to the deaf?
Alexander Graham Bell continued his experiments with his harmonic telegraph to end deafness.
Were there any other inventions from Alexander Graham Bell besides the harmonic telegraph ?
Alexander Graham Bell was credited with inventing and patenting the first practical telephone.

Question: Is there anything else interesting about Bell's later inventions?
Self-contained rewrite: Is there anything else interesting about Bell's later inventions besides the 14 patents as well as the wide range of bredth which his inventions covered?