Scientific Apparatus
Thompson's Notebook
The Archives hold a recently identified notebook kept by Charles Abbot
Thompson, class of 1881, which presents the sort of first-hand evidence
about which historians of science dream. The mathematics and physics
curriculum at Williston in the 1870's followed closely that of the
colleges. This was a transition era in which students were just
beginning to perform experiments on their own, supplemented with
demonstrations by the instructor. Physics was studied in the
penultimate year, using a textbook based on the standard text written
for Yale students by Denision Olmsted, updated and modified by Ebinezer
Snell of Amherst.
In 1879-80 Thompson studied physics with Roswell Parish, master (i.e.,
headmaster) of Williston's Scientific wing. Thompson recorded the notes
which Parish almost certainly wrote on the blackboard, and made
careful, detailed pen-and-ink drawings of the apparatus. These
drawings, some of which are reproduced on the next pages along with
descriptions of the instruments, are a vital link to the present
collection of historical scientific apparatus and to the history of
science instruction at Williston Northampton.
On this page we give some examples of the apparatus, along with Charles Thompson's drawings.
The Dielectric Machine
The Dielectric Machine is a most unusual form of electrostatic
generator. Turning the crank causes an electric charge at a high
voltage to collect on the metal terminal at the top of the apparatus.
The charge produced by this machine could be used to make a person's
hair stand on end, set up a cascade of sparks, and other
spectacular demonstrations rarely done today.
The Gunpowder Bomb
Either a Leiden jar or the Dielectric machine could be used to explode
the corked Gunpowder Bomb. This was supposed to demonstrate the effects
of electricity, but was equally effective in awakening sleepy students.
The Hydraulic Ram
In this device, water falling down the
pipe compresses air in the small glass dome, forcing water in the
center container to be lifted higher than its source, producing a
fountain at the top of the apparatus. The Williston specimen is unique in this country.
Snell's Wave Machine
This device demonstrates the progression of sound waves. As the crank
is turned, the individual balls go from side to side, and the pattern
of compressions and rarefactions moves sideways.
The design is
by Ebinezer Snell, who taught physics at Amherst College from 1825 to
1876. It was built by the Boston firm of Ritchie, and sold for $25.00
in 1860. Interestingly, the device in Thompson's drawing is clearly a
different instrument than the one which survives in the Williston
collection.
The Vacuum Pump
Williston Seminary's Vacuum Pump was one of the larger models available
in the second half of the 19th century. In Thompson's drawing, the pump
is being used to evacuate the space under a bell jar to show the
effects of the buoyancy of air. The apparatus collection
includes fragments of a demonstration, illustrated below left, in which
atmospheric pressure acting on one side of an evacuated cylinder lifts
a considerable weight.
Electric Engine
This device was developed in the 1840s by Charles Grafton Page, a
Harvard M.D. who became the United States' first professional inventor.
The model shown was manufactured in Boston some years later. Its
walking beam shows the influence of steam engine design.
Atwood's Machine
The heart of Atwood's Machine is the low-friction pulley at the top,
over which a light string is passed with almost-equal weights at either
end. The clock is used to time the fall of the masses, which can be
used to find the acceleration due to gravity. The design was published
by George Atwood of Cambridge University in the last decade of the 18th
century.