RMS Standard Gauges in Case, 19th Century

Five pairs of RMS standard eyepiece and sub stage ring and plug gauges in a wooden case, with key. Five of the gauges are ring-shaped and are various thicknesses. The other five "plug gauges" are shaped like bottles and are of various sizes. These are 1.572, 1.41, 1.27, 1.04 and 0.9173 inches. The mahogany case has a hinged lid with a plaque in the centre, and a locking mechanism. The key sits in the lock.