1To Benjamin Franklin from John Bartram, 29 July 1757 (Franklin Papers)
Letterbook copy: Historical Society of Pennsylvania I now take the Freedom of thy usual Benevolence and favour of thy wife to inclose this letter in hers hopeing this way we may keep the chain of friendship bright while thee art diverting thy self with the generous conversation of our worthy friends in Europe and adding dayly new acquisitions to thy former extensive stock of knoledge by thair...
2To Benjamin Franklin from John Bartram, 12 November 1757 (Franklin Papers)
Extract: The Royal Society Here is a visible Aurora Borealis; at 7 a Clock it was about two hours high, to the northward pretty bright. Soon after Day light disappeared it was much more East, where it was redder with some faint streamers, whose Points reached near 45 Degrees Elevation, which soon disappeared, and the Light descended by Degrees under the Pole, and by 10 a Clock was near...