noun
Meaning 1
Either of a pair of large copper hemispheres, with mating rims, that were used to demonstrate the power of atmospheric pressure. When the rims were sealed with grease and the air was pumped out, the sphere contained a vacuum and could not be pulled apart even by teams of horses.
Definition source: English Wiktionary via Wiktextract
Usage: historical
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided