This volume contains calculations of the distances of stars, eclipses, and longitude, made by William Maule, James Cresson, Joseph Jeanes, James James, and Robert Hutchinson, pupils in the Friends Academy, where Roberts was a teacher.

Notes kept by the Yale undergraduate John Austin Stevens on 20 lectures on natural philosophy delivered by Jeremiah Day during the fall, 1812. Includes lectures on gravitation, mechanics, and hydrostatics (hydrology), the last including theories of rivers, springs, and groundwater.

By an unknown author, this notebook is of experiments and the history of experiments with electricity, containing references to Franklin, Beccaria, and Priestley, etc.

Featuring the work of at least ten different authors, this collection includes several, unrelated meteorological observations from the mid-18th Century to the early 19th Century. While the majority of these records depict weather patterns in Philadelphia, there are also descriptions for Delaware, New England, London, and South America among others.

In 1839-1840, the ichthyologist Richard Parnell left London for a collecting expedition to Jamaica and a tour of museum collections in the United States. An authority on both fishes and grasses, Parnell published two noted works as a young man, his Prize Essay on the Natural and Economical History of the Fishes Marine, Fluviatile, and Lacustrine, of the River District of the Firth of Forth (Edinburgh: Neill and Co., 1838) and The Grasses of Britain, 2 vols. (Edinburgh: Blackwood, 1842-1845). He appears, however, to have abandoned publication in 1845, although he continued collecting for many years. The notebook kept by Richard Parnell during his voyage to the West Indies and United States in 1839-1840 contains little narrative, but dozens of pencil and watercolor sketches of the marine life that absorbed his interest, primarily fishes. Most sketches are accompanied by brief notes on the anatomy of the fish, sometimes with close-ups of fin structures, air bladders, or the digestive tract and stomach. Although collecting localities are seldom recorded, the majority of specimens seem to have been collected in Jamaica, with at least a few observed in vitro at the New York Museum.

These notes were kept by Ewing of medical lectures he attended, given by Drs. Nathaniel Chapman, John R. Coxe, and Philip S. Physick. The lectures concern fevers, materia medica, surgery, and diagnosis.

This is a small group of letters written to Johann Ambrosius Beurer, J. von Sprehelson, and Christoph Jacob Trew.

Miscellaneous letters from and to Benjamin Smith Barton, Nicholas Collin, Henry Muhlenberg, Jeremy Belknap, Monsieur Le Roi, and a broadside by Robert Aitken. These letters concern botany and zoology in the U.S., England, and on the Continent, and mention contemporary figures as well as the American Philosophical Society.

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.

The letters in this small collection concern the Smithsonian Institution, the Colorado Territory, and Humboldt's observations, among many other topics.