Richard Sheepshanks was a member of both the Commission of 1838 for considering the modes of restoring the national standards of weight and length, and of the Commission of 1843 for superintending the actual constructions. In 1844 he volunteered to undertake the reconstruction of the standard of length. As part of this work, conducted in a cellar beneath the Royal Astronomical Society's rooms at Somerset House, he commissioned a Comparing Apparatus which would be both mechanically firm and free from the effects of temperature. The comparisons attained on the apparatus were considered vastly more accurate than any made by his predecessors. The drawings in this series include eight figures (for an unidentified publication) and five further drawings relating to standards of length.