75/2259 (Hydrometer). Case w. hydrometer w. sm. ball on narrow stem with graduations for measuring, engr. ''J.B. 489'', sm. thermometer, engr. ''to. Blake. London'', 8 loose weights (?) and a glass graduated cylinder, n.pl., n.publ., n.d. (±1850), together in 19th cent. mahogany wooden red velvet-lined case, 15x11x6 cm.

- Cloth sl. discol. = In very good condition. The hydrometer measures the relative density of liquids.