Archimedean screw made for King George III by George Adams, Fleet Street, London, in 1762. Mounted on adjustable frame, with ivory ball in tin box.

The archimedean screw bears the inscription 'Made by Geo Adams Mathematical Instrument Maker to His Majesty' and was made for King George III in 1762 by George Adams, just after he ascended the throne in 1760. The full-scale archimedean screw was desinged to raise water, but Adams' model, which he described it in his course on Mechanics, was demonstrated using an ivory ball. Turning the handle causes the ball to travel up the length of the screw. When the ball reaches the top of the screw, it is dropped into the funnel and chanelled back to the bottom in a copper pipe, which makes a continuous action.