This account of Thomas Godfrey was prepared "with a view of having it inserted in Rees Cyclopedia," and is preceded by an essay concerning Godfrey and his quadrant taken from the "American Magazine" (1758). Also included in this volume is a copy of James Logan's communication to the Royal Society, and a letter from Spencer to Alexander Wilson, editor of the "Cyclopedia" (1809), which discusses Godfrey and the sources for this account.

This is a miscellaneous collection of letters, almost all written to Smyth by prominent scientists. The topics discussed include astronomy, microscopes, nautical almanacs, and submarine excursions. Also of interest is a letter from Thomas Graves, reporting what the Beagle (Charles Darwin's voyage) was encountering in South American waters.