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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.
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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.
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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.
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Glass
Samples and Mirrors #10647, 10650 and 10651
Unsigned
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).
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Microscopic
Polarization Apparatus #10328
Unsigned
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.
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