- In 1851, knowing that distillers in New York desired a hydrometer that would be more reliable than that designed by Southworth. James Adams produced a silver instrument that corresponded with the glass standard kept in Washington. The new hydrometer had an egg-shaped flotation ball, a weighted ballast ball, and one weight to be used with heavier liquids. The oval stem was graduated from 100 (pure alcohol) to 0 (proof) to 100 (pure water), and was correct for 60 degrees F. Adams also provided a thermometer and printed scale for temperature corrections. The distillers were satisfied. Judges at the New York Crystal Palace of 1853 granted a bronze medal and a “Special Approbation for Accuracy” to Adams & Tagliabue, Adams being the maker, and Giuseppe Tagliabue the distributor. Adams also won a diploma at the American Institute Fair of 1857. The first 153 of these hydrometers were numbered, and marked “Adams & Tagliabue.” Numbers 154 to 392 were marked simply “J. A.” Those made after 1 June 1857 were marked “James Adams.”
- In 1860 Adams applied for a patent on a hydrometer with a silver stem and a bulb of vulcanized india rubber, gutta percha, or any other such substance which, unlike copper or silver, was unlikely to be deformed if handled roughly. Since hydrometers made of metal or of india rubber were well known, the Patent Commissioner refused the application. The Appeals Court, finding that Adams' instrument united the advantages of the two dissimilar materials and avoided the objections of each, ordered that the patent be granted.
- Since this example came from the Patent Office, it is probably the model that Adams submitted with his patent application. The ballast ball is made of silver; the stem is graduated with two different scales, and marked “James Adams.”
- Ref: James Adams, Description of the Standard Silver Hydrometer (New York, 1857).
- James Adams, “Hydrometer,” U.S. Patent 31,100 (Jan. 15, 1861).
- Currently not on view
- Object Name
- Physical Description
- silver (overall material)
- hard vulcanized india rubber (overall material)
- overall: 6 3/4 in x 1 1/2 in; x 17.145 cm x 3.81 cm
- overall: 6 5/8 in x 1 1/2 in; 16.8275 cm x 3.81 cm
- ID Number
- accession number
- patent number
- catalog number
- See more items in
- Medicine and Science: Physical Sciences
- Data Source
- National Museum of American History
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