In a 1762 letter thanking Italian physicist Giambatista Beccaria for supporting and defending his recently published theories on electricity, Benjamin Franklin gave Beccaria permission to freely use, and instructions on how to build, one of Franklin’s new inventions:
Perhaps…it may be agreeable to you, as you live in a musical country, to have an account of the new instrument lately added here to the great number that charming science was before possessed of: — As it is an instrument that seems peculiarly adapted to Italian music, especially that of the soft and plaintive kind, I will endeavour to give you such a description of it, and of the manner of constructing it, that you, or any of your friends, may be enabled to imitate it, if you incline so to do, without being at the expence and trouble of the many experiments I have made in endeavouring to bring it to its present perfection.
The invention Franklin was describing was the glass armonica, a musical instrument that sounds like wine glasses being resonated with a wet finger, and works on exactly the same principle. The purpose-built glasses (bowls) in a glass armonica are mounted close together, though, so multiple perfectly-tuned notes are accessible within a hands-width, and since the bowls are rotated on a spindle one need only lightly touch them, as opposed to using a circular hand motion to resonate them. Tonight’s amusement en route to the Tips is almost certainly the most well-known piece of music to feature the unique and ethereal sound of the glass armonica: From Tchaikovsky’s ballet The Nutcracker, here’s William Zeitler playing Dance of the Sugar Plum Fairy.
You are invited, as always, to provide your Reader Tips in the comments.


