Letters on Astronomy by Denison Olmsted

Since the first publication of these Letters, in 1840, the work has passed through numerous editions, and received many tokens of public favor, both as a class-book for schools and as a reading-book for the family circle. The valuable discoveries made in the science within a few years have suggested an additional Letter, which is accordingly annexed to the series in the present revised form, giving a brief but comprehensive notice of all the leading contributions with which Astronomy has of late been enriched.