Collection of letters written primarily to William Cranch Bond, astronomer and first director of Harvard College Observatory. The collection includes letters written to colleagues of Bond such as Benjamin Peirce, and R. T. Paine, but all letters are docketed in Bond's hand.             A most interesting scientific correspondence featuring letters from the most prominent American astronomers and mathematicians of the period of 1840-1850 discussing a variety of pertinent topics: meteorological and magnetic observations, meteors, comets, planets, Mercury, Saturn, the recently discovered Neptune, telescopes and observatories, scientific applications of the electric telegraph, among other topics.     November 30, 1840, Philadelphia, Alexander Dallas Bache1, to William C. Bond, Cambridge "Dear Sir,         I received last evening your letter of Nov. 24 & thank you for so prompt an answer. There are still some points on which I must trouble you further. I find on comparing our Aurora for the May term, that with general coincidences there are some singular differences which perhaps in part were due to actual differences of phenomena but perhaps also in part to differences in instruments & modes of observing. Please inform me if your results are the mean of 5 ... at each time or of three.… more >