Fowlers Curved Urethral Sounds, American, c. ¾ 19th century.  This is a complete set of six double-ended finely polished, graduated, metal sounds numbered 9-20, and all contained in the original long leather bound wood case.
An identical set is listed in the 1890 Sharp and Smith catalog, as “Dr. Fowler’s set of sounds” having “the regular Van Buren curve and taper.”  They are designed for dilating the male urethral canal, for locating strictures, and for sounding for the presence of bladder stones.