This micrometer eyepiece is part of the transit instrument (aka meridian circle) made by William J. Young, in Philadelphia, and installed in the new observatory at ...

Wool bunting pennant flag. White field with a red border on the hoist edge. Blue square machine-stitched in the middle of the flag. White cotton hoist with no grommets. The inscription on the hoist ...

Wool bunting tapered swallowtail flag. Blue field with two diagonal white stripes, or bends, that extend from either end of the hoist to the end of each tail. The stripes cross at the fork of the ...

Barden Precision Ball Bearings of Danbury, Connecticut created this display of their precision ball bearings around 1950. Eight small ball bearings are embedded in an acrylic plastic block, displaying ...

This hinged dissection has two triangular pieces that may be arranged as a triangle or a quadrilateral. There is a model of a triangle with its medians which Wheeler variously designated 6K and 12TD.

This component consists of one brass and one steel gear held together by a cylinder. Parts of the Bush differential analyzer surviving at the Smithsonian have museum numbers MA.314824 and 1983.3002.01 ...

Each of these five aluminum spiral gears has a hole in the center. The dimensions are for each gear. A mark reads: 146335 6. Parts of the Bush differential analyzer surviving at the Smithsonian have ...

These five pieces can be arranged as a square two ways. A sheet in the case shows the solution. A mark on this container reads: Puretest (/) Aspirin (/) Tablets (/) U.S. 902. This is Wheeler's model ...

Physical Description: silver (overall color)metal, plastic (overall material)Measurements: overall: 4 in x 22 in x 20 in; 10.16 cm x 55.88 cm x 50.8 cm ...

PaceSetter Sewing Machine (Brother); 1954-1956; with portable case, Made by the Brother Sewing Machine Co. in Japan. Illustrative of the work of inventor Solomon Adler.

One signal amplifier on rectangular plastic circuit board. Apparently one of these preamplifiers would have been plugged into one corresponding socket of Mulitwire Proportional Chamber 1989.0050.01.1.

Obverse Text: 20 / FEDERAL RESERVE NOTE / THE UNITED STATES OF AMERICA WILL PAY TO THE BEARER ON DEMAND TWENTY DOLLARS / C / 12-L / L12013259A / AUTHORIZED BY FEDERAL RESERVE ACT OF DECEMBER 23, 1913 ...