This is a CHAS. FRODSHAM pocket watch movement serial number 9803. This is the highest grade of watch movement manufactured by this renowned London watch and chronometer maker. The letters AD Fmsz which appear on both the dial and the back of the movement were only used by FRODSHAM to designate watch movements built to exacting standards and which exhibit the superb workmanship and finish characteristic of the golden age of English watchmaking exhibited in the late 19th and early 20th century. Details of construction include a high degree of polish on components, diamond end stones on the balance wheel jewel settings, and the use of the rare Adolphe Nicole setting mechanism.