Convert from shaftment [ancient] to bohr

Unit Definition (shaftment [ancient])
A shaftment, when used as a unit of length, is usually six inches or two palms, i.e. 15.24 cm (for the international inch). It is thought to be the distance from the tip of the outstretched thumb to the other side of the palm.In English this unit has mostly fallen out of use, as do others based on the human arm: digit (1/8 shaftment), finger (7/48 shaftment), palm (½ shaftment) hand (2/3 shaftment), span (1½ shaftments), cubit (3 shaftments) and ell (7½ shaftments).

Unit Definition (bohr)
The Bohr is a unit of distance commonly used in particle physics. It was named after the Danish physicist Niels Bohr (1885-1962), who explained the structure of atoms in a famous paper in 1913. The Bohr radius represents the mean distance between the proton and the electron in an unexcited hydrogen atom. It equals about 52.918 picometers (pm), or 52.918 x 10e-12 meter.