Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Furnishings and Equipment (hierarchy name)
4. Tools and Equipment (hierarchy name)
5. equipment
6. [equipment by profession or discipline]
7. [equipment for science and technology]
8. scientific instruments
9. chemistry equipment
10. chemical testing devices

Anotations

Scope note:

Laboratory apparatuses used for collecting samples of pure gases such as hydrogen, oxygen, and nitrogen. These are of varied size and made from glass, metal, or plastics, and depend on the transfer of gas from one vessel through water contained in another. The original concept was developed by Reverend Stephen Hales ca. 1727.