Glass and Mercury Antique Hydrometer in Original Wooden Box matches I believe one is ebony

I believe one is ebony and the other two are either walnut or teak

I found this one at an estate sale in Lowell

These pages are preceded by an introductory section addressing such questions are "What Is Modern

One might put a few favorite rocks in it

I just want to snuggle up with it

Glass and Mercury Antique Hydrometer in Original Wooden Box matches I believe one is ebonyAt first I thought this antique Griebel Instrument Co. hydrometer was an old thermometer, until I noted that the numbers on the side run 0 to 6 rather than showing temperatures. Ive since learned that a hydrometer is used for measuring the relative density of liquids based on buoyancy: you pour liquid into a container, lower the hydrometer into it until it floats, and then the point at which the surface of the liquid touches the stem of the hydrometer