Bond's track gauge. It comes from a 15-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 track gauge is thought to have belonged to a much later member of the family who was involved in the packing up of artifacts ready for auction as Observatory House was cleared in the late 1950s.