These volumes contain calculations and drawings of an eclipse of the sun, 24 June 1778, and of the moon, 29 May 1779, adjusted to the meridian of Philadelphia. There is also an incomplete duplicate of the calculations for the sun, and a duplicate of the calculations for the moon. An apparently personal reference in the text suggests that Freehauff was a native of Germany.

During the late eighteenth and early nineteenth centuries, the American Philosophical Society regularly received letters, and occasionally full blown manuscripts, from members of the public regarding their ideas on science or technology. In 1829, Edward Mulhern of Philadelphia submitted a manuscript on terrestrial magnetism that he felt had implications for navigation. Little is known about Mulhern other than that he died before 1833. Mulhern's "Dissertation on the doctrine and principles of magnetism &" is an attempt to work through some fundamental issues in terrestrial magnetism, including the relative orientation and positions of the geographic and magnetic poles, with an eye toward their impact on navigation. The APS Minutes for April 15, 1833, read: "An application from Alex Mulhern to have returned to him a paper on the 'doctrine of Magnetism' laid before the society by his deceased father, was received and the Librarian was directed to return the same.'"

This diary is an account of a voyage from Newport (R.I.) to London, with descriptions of Boston, Dover, Edinburgh, and London. There are also many references to Benjamin Franklin in the diary.

This item also contains some newspapers clippings and a manuscript obituary of Julian Halliday Coxe (1833-1834), infant son of Daniel T. Coxe.

Charles Morton's "System of Physicks" was among the most important texts in natural philosophy in early America, used to teach science and the scientific method to students at both Harvard and Yale from the late 1680s through the 1720s. This fair copy was probably transcribed at one of those institutions in about 1700, and is a fairly complete accounting of Morton's best known work.

This essay discusses Priestley's experiments concerning phlogiston, also called "the principle of inflammability," which was once thought to be a volatile substance that was part of all combustible matter and was released as flame in combustion.

This small volume records excerpts from British natural philosophy and scientific journals, written sometime after 1799. It covers a wide range of subjects, from astronomy to zoology.

This is an extract from a manuscript and is divided into three parts. This volume puts forth the theory that the visible geological formations of the earth were formed in the depths of the ocean; it offers opinions that support this system; and then predicts the natural consequences of the loss of all living beings from the waters of the ocean.

This volume was copied by Philip Holbrook Nicklin, a Philadelphia author and bookseller, from portions of the "London Quarterly Journal of Science Literature and the Arts" and partly from a translation of the original, to which is prefixed a short conchological introduction, containing descriptions of the Linnean genera, & of those species, from which Lamarck has formed most of his genera.

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 volume contains extracts, chiefly in an unknown hand (probably Charles Waterton), from Ord's letters, 1831-1835, criticizing Audubon as a man and as a naturalist. Ord wrote the last part of the volume (signed and dated June 29, 1838), and there are manuscript comments by Charles Waterton.

This work contains some material on electricity. There are also 14 plates, representing the essential elements of mathematics, physics, and cosmography.

The first volume contains mathematical problems, which appear to be college exercises (1814); the second volume is an essay on the projection of the sphere and spherical trigonometry, including an appendix on astronomy (1812); and the third volume is a lecture on natural philosophy, apparently prepared for delivery [n.d.].

This volume includes several printed and manuscript items related to the death of Caspar Wistar, in January 1818.

An early Welsh emigrant to Pennsylvania, David Evans was educated at Yale (1713) before answering the call to Presbyterian pulpits in the Welsh Tract of Delaware and Pennsylvania, and to the church at Pilesgrove, N.J. Written entirely in Latin in 1747 when Evans was 66 years old, the Aliquot Rudimenta Physicae consists of four separate compendia bound together, the Compendium Technologiae, Logicae, Rhetoricae, and Physicae. The work is an interesting and thorough attempt to summarize a system of knowledge with impeccable American provenance.

This treatise includes experiments on eletricity (with mentions of B. Franklin), ballooning (mentions of J. P. Blanchard), pharmacology, chemistr, and hydraulics. Included is a sketch of Woulfe's bottle for passing gases through liquids (Peter Woulfe, 1767).

The papers of the Italian natural philosopher and electrician, Giambatista Beccaria (1716-1781) contain letters to Benjamin Franklin, Joseph Banks, Laura Bassi, Gian Francesco Cigna, and others on a variety of scientific topics, including atmospheric and terrestrial electricity, the aurora borealis, earthquakes, meteorology, and phosphorescence. In addition to Beccaria's epistolary essays, the collection includes several journals of meteorological observations and notes for Giovanni Eandi's biography of Beccaria.

There are botanical notebooks which concern Bunbury's study of fossil plants in general, with special studies on the fossil plants in the Geological Society in Richmond, Virginia, and at Aix-la-Chapelle, Cape Breton Island, and Pennsylvania. There is also a historical sketch of eminent English naturalists.