Brace, Skinner
and Tuckerman:
Optics in the Heartland
John N. Howard
In the late 1800s, the University of Nebraska
became the first school west of the Mississippi
to award a doctoral degree. It also gave optics
three bright stars and early leaders.
University of Nebraska physics department, May 1905. Left o right, Front row: Burton Evans Moore and Bertram Spencer. Middle row: De Witt Brace, John Almy and J.M. Chowins. Back row: Clarence A. Skinner and an unidentified man.
The University of Nebraska opened its doors in 1871. Its first phys-
ics teacher was a Lutheran minister by
the name of Samuel Aughey, who had
once worked at the Smithsonian under
Joseph Henry. He taught all the courses
in chemistry, physics, astronomy, botany
and geology, and even
a course in German.
As the university grew,
several scholars were
added to the faculty,
including DeWitt
Bristol Brace, who
came to Nebraska
in 1887. Brace had
a degree from MIT,
and he had done some
graduate work at Johns Hopkins with
Henry Rowland. He had finished a
Ph.D. at Berlin, working under Helm-
holtz and Kirchho;. During a one-year
trial period, he taught six physics courses
in addition to supervising the physics
laboratories. At the end of the year, he
was made a full professor and chair of
the physics department.
Since cities in the United States were
rapidly becoming electrified, Brace
initiated new courses in what we now
call electrical engineering. When one of
John Howard
Brace’s students was awarded a Ph.D. in
1896, it was the first doctoral degree given
by any school west of the Mississippi. A
few years later, Louis Bryant Tuckerman
Jr. became a graduate student under new
faculty member Clarence Aurelius Skinner. Tuckerman was born near Cleveland
in 1879 and had earned a degree in physics from Western Reserve University.
By 1900, Brace had found the time
to do some research of his own, and he
chose the field of optics. He decided to
investigate the negative results obtained
by A.A. Michelson and Edward Morley
in their experiment measuring ether
drift. ;e best known of Brace’s ether
drift measurements was one on the dou-
ble refraction of light; he published it in
Phil. Mag. in 1904. For that, he repeated
an experiment that Rayleigh had sug-
gested in 1902, to test the idea that light
polarized parallel to the direction of the
ether drift would have a di;erent velocity
in a medium from light polarized per-
pendicular to that direction, thus caus-
ing the medium to be doubly refracting.
Brace refined Rayleigh’s experiment by
designing a much more sensitive polarim-
eter. ;e sensitivity of Brace’s apparatus
was more than 300 times greater than the
Michelson-Morley experiment. Neverthe-
less, he also detected no ether drift. His
results were quoted immediately by H.A.
Lorentz and Edward Nichols, and they
were considered definitive.
18 | OPN Optics & Photonics News
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