ID:
2404
Maker's Name:
John J Griffin
Where made:
England
Dimensions:
13 × 13 × 30 cm
These were used to demonstrate that the Earth's atmosphere exerted a force on surrounding objects.
The hemispheres were held together, and air exhausted from the interior.
As the atmosphere exerts about 15lb/sq in force or 100kPa pressure, it requires a large effort to pull the hemispheres apar.t
Book reference:
Scientific Handicraft, AN ILLUSTRATED AND DESCRIPTIVE CATALOGUE OF SCIENTIFIC APPARATUS ,Item 1-5910 4 1/2 inch brass
