Silk twisted for use in Bailey's torsion experiment in a bag. This silk comes from a 14-drawer cabinet found in the Herschel family home in the 1950s. The contents of this and a similar cabinet seem to suggest that they were used by successive generations of the family to store specimens, material and apparatus for carrying out experiments. This silk, as stated on its packaging, was obtained for use in Bailey's torsion experiment.

Bailey's torsion experiment was essentially a repetition of the Cavendish Experiment to measure the density of the Earth with the use of a pendulum. John F.W. Herschel and his son John had a long running correspondence about this while the latter was stationed out in India with the Royal Engineers. John (junior) even published papers on the subject in the Transactions of the Royal Society of London.