Sorry for the lack of posts. Been very busy this semester between classes (why did not anyone tell me how much reading history graduate students must do?). Just finished transcribing another set of 50 letters. My fellow transcriber is house-sitting in Scotland (yeah, house-sitting in Scotland!), and she took letters with her to work on.
I am planning a research trip to London for this fall. The archives of the Royal Insititution of Great Britain hold the most material available on Tyndall. You can see the scope of that collection here.