historical scientific instrument gallery

mechanics and misc
heat and properties of matter
wave motion and sound
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Select an item to view from the list below or browse through the entire collection. To view an enlargement click on the photo.

Polarimeter #10044
Schmidt & Haensch, Berlin

Certain substances, such as sugar solutions, have the ability to rotate the plane of polarization of light. The angle of rotation depends on the path length of light in the solution and on the concentration. A polarimeter has a polarizer to produce plane-polarized light, a place for the sample through which the polarized light passes, and an analyzer to measure the angle of rotation.
Reference: Max Kohl Catalogue No. 100 (c.1927) p.456.
Saccharimeter #10075
Franz Schmidt & Haensch, Berlin

A saccharimeter is a polarimeter especially designed to determine the sugar content of candies, syrups, urine, etc. The center section opens up to insert observation tubes of calibrated lengths containing the solution to be tested. This instrument, purchased by DeWitt Bristol Brace in 1889, contains a Lippich half-shade polarizer. This consists of two prisms, the larger of the Glan-Thompson type and the smaller a half-shade prism, which covers half the field of view. One telescope is to view a double vernier scale for measuring angles. The Lippich polarizer is the most sensitive and an instrument of this type sold for almost $800 in 1927.
Reference: Eimer & Amend BCM Catalog (1927) p.645.
Polarimeter Standards #10657
Schmidt & Haensch, Berlin

This beautifully finished set of five polarimeter tubes has carefully made quartz disks that are used to calibrate polarimeters.
Glass Samples and Mirrors #10647, 10650 and 10651

These items were used by D.B. Brace in his optical researches. The cylinder is of Faraday glass 22 cm long with an index of refraction of 1.76. Two of these were used in his 1897 experiment on the propagation of light in a dielectric normal to a magnetic field. The large glass slab is of crown glass and measures 42 x 10 x 3.2 cm. It was one of the two media that Brace used in his famous 1904 experiment on the effect the Earth’s motion through the ether has on the double refraction of light in a medium. The concave mirror was also used in that experiment to focus the light beam.
Reference: D.B. Brace, Philosophical Magazine, series 5, 48, 342-49 (1897) and series 6, 7, 317-29 (1904).
Microscopic Polarization Apparatus #10328

Ordinary unpolarized light striking a surface at a certain angle, known as the Brewster angle, is reflected as plane polarized light. This instrument has mirrors for reflection and a magnifying system to examine the axial image.
Reference: Max Kohl Catalogue No. 100 (c.1927) p.451.