The cup, so inverted, served as a socket to receive a steel pivot rising from a cavity made into a round piece of light wood or cork which thus forms the compass-box. The surfaces of the socket and pivot, intended to meet each other, are perfectly polished... Tijdschrift voor de wis- en naturkundige wetenschappen, uitgegeven door de ... - Pagina 10 door Nederlandsch instituut van wetenschappen, letterkunde en schoone kunsten - 1851 Volledige weergave -
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