[Written in 1755, they'd be too early to mention the glass armonica, which Franklin invented in 1761. Nevertheless...]
British Copies Found of Ben Franklin Letters
New York Times
A professor from the University of California, San Diego, who was researching Benjamin Franklin at the British Library made a discovery on the last day of his trip in 2007: copies of 47 letters by, to and about Franklin that were written in the spring and summer of 1755 and not seen since. The university said that the letters, which were found by Alan Houston, a professor of political science, had been copied by Thomas Birch, a Franklin contemporary who was a prodigious transcriber and compiler of historical documents and later became secretary of the Royal Society. They were written to and from Franklin’s son William and his wife, Deborah, as well as the British general Edward Braddock, and cover a period during the French and Indian War when Franklin helped organize a Pennsylvania militia against the forces that threatened the colonies. The letters are being published in the April issue of The William and Mary Quarterly.