Twin Wheels Coupled by Pins, One Turning, One Fixed
A graduated wheel numbered 200-100-400-20-10, with a measuring arc and disc device below
Two large compass-drawn wheels dominate the upper sheet, joined at their centres by a pinned coupling; a note directs that the pin of wheel a be kept in motion while pin b stays fixed. The upper wheel carries a run of numbers - 200, 100, 400, 20, 10 - read when the sheet is turned onto its right side, suggesting a graduated or counting wheel. Below, a compass-drawn quarter-arc scale and a small apparatus of stacked discs appear, beside the note 'this is the middle'. Further faint construction lines and untranscribed jottings are present.
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Two wheels linked by pins a and b
A pinned coupling joins the two large wheels at their centres. The instruction is that the pin of wheel a be kept in motion while the pin b remains stationary, so one wheel works against the other.
Graduated upper wheel numbered 200-100-400-20-10
When the sheet is turned onto its right side, the upper wheel shows a sequence of numbers - 200, 100, 400, 20, 10 - marking it out as a graduated or counting wheel.
Graduated arc and disc device
The lower half carries a compass-drawn quarter-circle serving as a scale, beside a small apparatus of stacked discs; the adjacent note reads 'this is the middle'.