Nydrometer (specifically a lactometer or spirit hydrometer)
Entry/Object ID
100388
Scope and Content
(AI) This multi-part metal instrument is an antique hydrometer (specifically a lactometer or spirit hydrometer) complete with its original tin storage cylinder and cap.
Function: Used in the 19th and early 20th centuries to measure the liquid density or specific gravity of liquids—most commonly used on farms to test milk quality/fat content (lactometer) or in distilling to check alcohol proof.
How It Works: The weighted bulb at the bottom acts as a counterweight to keep the tool upright when floated inside the tall tin cylinder filled with liquid. The thin, calibrated stem floating above the surface indicates the density reading on an engraved scale.
Components Pictured:
Weighted Hydrometer (Foreground): Features a hollow metal floating bulb, a weighted lead/brass base knob, and a long stem marked with gradation lines.
Storage Cylinder & Cap (Background/Left): The dark sheet-metal tube and cap designed to double as both a protective transport case and the testing cylinder to pour the liquid sample into.
Found in Box from Robert M Jackson
