Black slate stone in the form of a dodecahedron (a geometric solid with twelve flat faces). The side of each pentagon is about one and one half inches. Markings are incised on the faces.

Brass triangular base 10 1/2" wide, with three leveling screws and two spirit levels. Upon it a vertical stands carries a triangular frame pivoted at the base. Its long arm carries an adjustable, threaded contact screw. The arm at right angle to this is acted upon by a cam mounted on the stand. Movement of the cam causes a hand to move over a scale from 0 to 220, and the contact screw to rise vertically one inch per 100 divisions. (Robert P. Multhauf, "Catalogue of Instruments and Models," 1961).

Glass and Mercury thermometer with fabric strap, fabric case, and metal case. Glass of thermometer is etched with degree lines and the degrees 10 through 240, in ten-degree increments. Also etched "Farenheit." Presented with the papers of Charles M. Wheatley (APS Library).

Small leather-covered wooden box containing ten brass weights. Each weight is inscribed with letters and numbers. A slide covers a collection of ten (originally twelve) smaller silver weights, the largest of which is marked 128. Paper label on front of box labeled "German weights for coins".

Mahogany banjo-shaped case for hanging on a wall. Within is set a wheel barometer, controlling the needle of a dial set in the bottom, on which weather indications are given. A thermometer and hygrometer are also set in the front. Marked "Bishop, Portland St."

Brass construction. The instrument consists of a plate supported by an L-shaped arm and foot. A thumbscrew on the plate causes a pencil below to describe the figure, through a train of four gears, the last of which carries the pencil at the end of an arm. (Robert P. Multhauf, "Catalogue of Instruments and Models," 1961).

The telescope is made of brass and consists of a 33 1/2" tube on 25" axis with a 1 3/4" aperture and a focal length of 32". Mounted on a brass stand of two rigidly connected A-frames, for use on a table. There are crossed hairs in focal plane, semi-circular scale of 9" radius attached to the bottom of the tube, and a suspended spirit level. Its construction is generally in accordance with earlier European convention. Unmarked. (Robert P. Multhauf, "Catalogue of Instruments and Models," 1961).

Marked "Tho. Heath Londini Fecit." 19" telescope, mounted on 4" vertical and horizontal circles. On tripod. (Robert P. Multhauf, "Catalogue of Instruments and Models," 1961).

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).

Two blocks of wood, hinged to be closed for carrying. A compass is set in the lower block. Both blocks are scaled to the gnomon which is a thread extending diagonally between them. The cover block has on its exterior surface a rotatable wooden disc with pointer and scale. Marked with tables and scales in Chinese script. Down the sides of the dial are 13 holes for setting the angle of the lunar dial. (Robert P. Multhauf, "Catalogue of Instruments and Models," 1961).

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.

Brass instrument, with horizontal dial with a 5 3/8" needle and scale from 0 to 110. The needle is mounted on a vertical spindle about 5" long. The spindle is mounted on bearings at top and bottom, the latter being a needle in the center of a mica disc. A fine spiral spring extends over 4" of the spindle, and is attached to it at the bottom and to the frame at the top. The spindle and spring are covered by a brass housing which can be pulled off. Instrument has ill-fitting top which may not be original. Top is inscribed with "S. Homer May 27 1863" and "Samuel Homer Aug 27 1863."

Brass instrument on wooden stand. Inscription on brass says "Pixii, Neveu et Succeur de Dumotiez a Paris." Paper label on base says "The property of Dr. Hare value [?] Smithsonian."

Hydrometer consists of a buoyant brass sphere, from which weighing pans project above and below. Housed with seven weights in original wooden box, lined with felt. The weights are marked: 424, 384, 192, 96, 48, 24, 12.

Ten-pound precision balance in brass. Ivory balance indicators are mounted on columns of the supporting frame. The pans are supported by rigid rods suspended from the balance arm.

Unmarked except for a brass plaque (not original) stating that the battery was used by Benjamin Franklin. It contains thirty-five jars in seven rows of five, each jar having a height of 12 1/4" and a 2" square cross-section. Each is covered with foil to a height of about 9", and has a wooden cap from which contact wires project within. Through wires laid across the top, the jars are connected in series. This battery has been restored at some point in the past. Fifteen of the Leyden jars appear to be original; twenty are facsimiles and are so marked by a diamond point inscription on one side. The facsimiles were made in a mold which left a burr not present in the original, and are covered with foil on the outside only. (Robert P. Multhauf, "Catalogue of Instruments and Models," 1961).

Insulated glass container with platinum wires, brass, and mesh. Presented along with the papers of William Francis Gray Swann (APS Library).

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 variation transit (magnetometer), in oak box. Instrument has two telescope assemblies.

Marked "Potts and Rittenhouse." 6" compass set in 13 3/4" sighting arm with sights 6 1/4" high. On walnut tripod. (Robert P. Multhauf, "Catalogue of Instruments and Models," 1961).