wpid-2012-06-26_10-52-50_499.jpg September 20, 2012 500 × 375 Amazing and historic artifacts of science A letter by Ben Franklin written to a British colleague after witnessing the first manned hydrogen balloon flight. Like this:Like Loading... Share this:Click to email this to a friend (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on LinkedIn (Opens in new window)Like this:Like Loading...