Where a Suspended Rod Hangs: Centre and Obliquity
A rod hung off-centre settles at two equal acute and two equal obtuse angles to the plumb line
Two linked statements on the equilibrium of a suspended body. The first rule holds that the centre of any heavy figure lies on a plumb line directly below the centre of the cord that supports it. The second asks what tilt a rod hung from a single cord away from its midpoint will take, answering that it settles so that its opposite sides make two equal acute angles (a n m, o p q) and two equal obtuse angles (f o d, n m r) with the plumb line; a horizontal rod at the top and an oblique rod at the right, with the check-point h, illustrate the rule.
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Centre of gravity hangs below the cord
The centre of any heavy figure lies on a perpendicular line beneath the centre of the cord that suspends it. This general rule opens the page and underpins the analysis of the tilted rod that follows.
Obliquity chosen by a rod hung off-centre
A rod suspended by one cord away from its midpoint settles at an obliquity such that its opposite sides, with the plumb line of the cord's centre, form two equal acute angles a n m and o p q and two equal obtuse angles f o d and n m r. Point h confirms the agreement with the preceding proposition.