Pine case without embellishment. The dial is 10 5/8" diameter, probably of cold silvered brass. Unmarked. Heavy brass plates with a pillar at each of the four corners contain the deadbeat escapement and going train of two many-toothed wheels. The motion work is between the dial and front plate. A small gear on the #2 gear arbor drives a large gear carrying the minute hand. The hour hand is driven by the latter gear through a compound idler gear and pinion. The second hand is mounted on the escape wheel arbor. The pendulum vibrates seconds and is mercury compensated. It is in two pieces connected by a yoke, and suspended by two springs. A thermometer is mounted on the back of the case. (Robert P. Multhauf, "Catalogue of Instruments and Models," 1961).

Prior to 1895 the Dial existed as separate pieces in the collection. At that time, they were assembled in an incorrect configuration and have since been disassembled. A reproduction base in the shape of a figure of Hercules was made in 2001, but it is unlikely that such a figure would have been used on this piece. This compass may not be original to the piece, and its face and part of the gnomon are missing. The instrument is marked for equal and planetary hours, common and Italian hours, with appropriate conversion tables. The base is elaborately decorated with a Biblical relief of the two miracles of Isaiah, and the bowl with the Zodiac. This type of dial requires both a vertical gnomon and a diagonal gnomon. In the present example, the former would consist of a pointed rod in the center of the bowl (now occupied by a compass); the latter of a figure holding a staff (part of which is restored), mounted to the rim. A string from the center to the end of the staff would form the second gnomon. Engraved. "CHRISTOPHERUS SCHISSLER GEOMETRICUS AC ASTRONOMICUS ARTIFEX AUGUSTAE VINDELICORUM FACIEBAT ANNO 1578" along outer rim of the underside of the bowl.

Plaster model of a three-dimensional surface. The printed inscription reads, "Model of the magnetic surface presented in the discussion Part II of the magnetic observations made at the Girard College Philadelphia between 1840 and 1845, by Prof. A.D. Bache. Const. and modeled by Ferdinand Engel, Washington, D.C. 1862." A handwritten description reads, "Presented by A.D. Bache." The observations which this model records are described in a 36-page pamphlet published by the Smithsonian Institution in 1863. A note with the model states that Bache intended to make two more models of the horizontal and vertical forces; one of these is now at the Smithsonian.

A black walnut box containing two measuring tubes; one with 1 1/4" diameter screen disc and 5" long tube and one with 6" screen disc and 2 3/4" long tube. This is an experimental instrument fabricated of discs of bronze or brass screen, attached to a brass tubing to constitute an anemometer. (Robert P. Multhauf, "Catalogue of Instruments and Models," 1961).

Nine instruments housed in original wooden case covered in leather or sharkskin. The top of the case is hinged at one side, and held shut by a snap fastening. Inside the top is a printed label: "McAllister & Co./48 Chestnut Street/Philadelphia. Have constantly for sale, cases of/Mathematical Instruments/For Schools, Wholesale & Retail/Dividers, Gunter's Scales, Parallel Rules, Brass and Ivory Protractors, etc. separate from the case." Around the wall of the top is pasted a strip of paper, bearing handwritten inscriptions - "$3 1/4 /N60K/n fli/gfi DW Mr/ No 160-9/str purchd March 18 1847/of McAllister." Contains nine drafting instruments: divider, compass with five attachments, ivory scale, parallel rule, and scaled semicircle.

Brass instrument. In a box labeled, "J.H. Onderdewyngaart, Canzius a Delft. La Fabrique des instruments de physique et de mathematique a Delft." (Robert P. Multhauf, "Catalogue of Instruments and Models," 1961).

Brass circular box of 3" diameter, 1 3/4" high, into which is built a sextant. Unmarked.